Difference between revisions of "Colors in Matlab"

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__TOC__
 
__TOC__
 
==RGB colors==
 
==RGB colors==
−
For coding purposes colors are mostly specified in RGB, which stands for Red, Blue and Green. The values range from 0 to 1. As an example: the color red is given by the triple [1,0,0]. Since it is hard to know what a certain triple (e.g. [0.5, 1, 0.5]) stands for it is more easy to call them by their name.
+
For coding purposes colors are mostly specified in RGB-triplets. RGB stands for Red, Blue and Green. The values range from 0 to 1. As an example: the color red is given by the triple [1,0,0]. Since it is hard to know what a certain triple (e.g. [0.5, 1, 0.5]) stands for it is more easy to call them by their name.
  
−
We have created a few functions for RGB colors by their names:
+
Matlab has an build-in function for converting colornames to RGB-triplets:
 +
<pre>
 +
>>colorname = 'red';
 +
>>RGBtriplet = validatecolor(colorname)
 +
ans  =  1.0000  0.0000  0.0000
 +
</pre>
 +
 
 +
Valid color names are: 'red', 'green', 'blue', 'cyan', 'magenta', 'yellow', 'black' and 'white'.
 +
 
 +
==Other color formats==
 +
 
 +
Other ways to specify colors are: <br>
 +
*hsv (hue, saturation, and value) triplets:
 +
<pre>
 +
>> color = [0.7500    1.0000    1.0000]; % hsv code for 'indigo'
 +
>> RGB  = validatecolor(color)
 +
ans  = 0.5000  0.0000  1.0000
 +
</pre>
 +
 
 +
*uint8 triplets:
 +
<pre>
 +
>> color = uint8([127 0 255)]); % uint8 code for 'indigo'
 +
>> RGB  = validatecolor(color)
 +
ans  = 0.4980  0.0000  1.0000
 +
</pre>
 +
*uint16 triplets:
 +
<pre>
 +
>> color = uint16([32768 0 65535)]); % uint16 code for 'indigo'
 +
>> RGB  = validatecolor(color);
 +
ans  = 0.5000  0.0000  1.0000
 +
</pre>
 +
*hexadecimals:
 +
<pre>
 +
>> color = {'#8000FF'}; % hexadecimal code for 'indigo'
 +
>> RGB  = validatecolor(color);
 +
ans  = 0.4980  0.0000  1.0000
 +
</pre>
 +
*CMYK (cyan, magenta, yellow, black) quadruplets: not supported by Matlab
 +
 
 +
==Named colors in english, dutch, german and spanish==
 +
 
 +
We have created a functions in biofysica\utilities\colors for more RGB colors by their names in english, dutch, german and spanish:
  
 
* <RGBcolors>  for english names
 
* <RGBcolors>  for english names
Line 16: Line 57:
  
 
>>kleuren.FELROZE
 
>>kleuren.FELROZE
−
ans = 0.5000   0.5000   1.0000
+
ans = 1.0000  0.0000   0.5000
  
 
>>farben.BLAU
 
>>farben.BLAU
Line 24: Line 65:
 
ans = 0.0000  1.0000  0.0000
 
ans = 0.0000  1.0000  0.0000
 
</pre>
 
</pre>
 +
  
 
All the named colors are:
 
All the named colors are:
Line 86: Line 128:
  
 
==Color maps==
 
==Color maps==
−
You can make a color map for plots:
+
Color maps are used for plots like surface plots. Color maps are arrays with any number of columns and RGB values for every row. <br>
 +
There are 18 predefined color maps in Matlab with 256 colors each. These maps are accessible by <predefinedColormaps>.
 +
 
 +
* The default colormap is 'perula'.
 +
 
 +
<pre>
 +
myMap = predefinedColormaps.summer;
 +
colormap(myMap)
 +
surf(peaks); %make a surface plot with 'summer' colors.
 +
</pre>
 +
 
 +
You can view the color map by creating an instance of predefinedColormaps and call the method show:
 +
<pre>
 +
maps = predefinedColormaps;
 +
maps.show(perula);
 +
</pre>
 +
 
 +
When you want to see the current active colormap you can use: maps.show(colormap);
 +
 
 +
 
 +
 
 +
You can also define you own maps
 +
 
 
<pre>
 
<pre>
−
map = [RGBcolors.LIME, RGBcolors.BLUE, RGBcolors.MAGENTA];
+
mymap = [RGBcolors.LIME;...
−
colormap(map);
+
        RGBcolors.RED;...
 +
        RGBcolors.BLUE];
 +
colormap(mymap);
 
surf(peaks);
 
surf(peaks);
 
</pre>
 
</pre>
 +
 +
All MATLAB predefined color maps:
 +
 +
{| class="wikitable"
 +
! Name
 +
! Description
 +
|-
 +
| parula
 +
| A smooth, perceptually uniform colormap with blue-to-yellow transitions, default in MATLAB since version R2014b.
 +
|-
 +
| turbo
 +
| A vibrant, perceptually uniform colormap with a wide dynamic range, transitioning from blue to red via green and yellow.
 +
|-
 +
| hsv
 +
| A circular colormap representing the hue component in the HSV color space, cycling through the full range of colors.
 +
|-
 +
| hot
 +
| A colormap with transitions from black to red, then yellow, and finally white, typically used for thermal or intensity data.
 +
|-
 +
| cool
 +
| A simple linear colormap that transitions smoothly from cyan to magenta, often used for contrast with warm color schemes.
 +
|-
 +
| spring
 +
| A pastel colormap transitioning from magenta to yellow, often used to represent seasonal or thematic data.
 +
|-
 +
| summer
 +
| A light green to yellow colormap that gives a warm, sunny feel, used for representing continuous data.
 +
|-
 +
| autumn
 +
| A colormap with warm tones transitioning from red to yellow, evoking the colors of autumn leaves.
 +
|-
 +
| winter
 +
| A cool colormap transitioning from blue to green, commonly used to represent water or icy conditions.
 +
|-
 +
| gray
 +
| A simple grayscale colormap, transitioning linearly from black to white, often used in intensity maps.
 +
|-
 +
| bone
 +
| A colormap with a grayscale base, but with a slight blue tint, designed for displaying images of bones and x-rays.
 +
|-
 +
| copper
 +
| A colormap transitioning from black to copper-brown, useful for visualizing data with metallic or heat-related themes.
 +
|-
 +
| pink
 +
| A pastel colormap with a gradient from dark to light pink, often used for softer data visualizations.
 +
|-
 +
| lines
 +
| A colormap with distinct, evenly spaced colors, designed for line plots with many different lines.
 +
|-
 +
| jet
 +
| A rainbow colormap transitioning from blue to red, previously the default in MATLAB, but criticized for non-uniform perceptual changes.
 +
|-
 +
| colorcube
 +
| A discrete colormap that uses a fixed set of distinct colors, typically used for categorical or label-based data.
 +
|-
 +
| prism
 +
| A repeating sequence of vivid colors, often used for periodic or cyclic data.
 +
|-
 +
| flag
 +
| An alternating red, white, blue, and black colormap, often used for data with binary or oscillating patterns.
 +
|}
 +
 +
Extra in biofysica\utilities\colors defined colormaps:
 +
 +
{| class="wikitable"
 +
! Name
 +
! Description
 +
|-
 +
| blueshades
 +
| A colormap with a gradient from dark to saturated blue.
 +
|-
 +
| redshades
 +
| A colormap with a gradient from dark to saturated red.
 +
|-
 +
| greenshades
 +
| A colormap with a gradient from dark to saturated green.
 +
|-
 +
| cyanshades
 +
| A colormap with a gradient from dark to saturated cyan.
 +
|-
 +
| magentashades
 +
| A colormap with a gradient from dark to saturated magenta.
 +
|-
 +
| yellowshades
 +
| A colormap with a gradient from dark to saturated yellow.
 +
|}

Latest revision as of 10:24, 25 September 2024

RGB colors

For coding purposes colors are mostly specified in RGB-triplets. RGB stands for Red, Blue and Green. The values range from 0 to 1. As an example: the color red is given by the triple [1,0,0]. Since it is hard to know what a certain triple (e.g. [0.5, 1, 0.5]) stands for it is more easy to call them by their name.

Matlab has an build-in function for converting colornames to RGB-triplets: 

>>colorname = 'red';
>>RGBtriplet = validatecolor(colorname)
ans   =   1.0000   0.0000   0.0000

Valid color names are: 'red', 'green', 'blue', 'cyan', 'magenta', 'yellow', 'black' and 'white'.

Other color formats

Other ways to specify colors are:

  • hsv (hue, saturation, and value) triplets:
>> color = [0.7500    1.0000    1.0000]; % hsv code for 'indigo'
>> RGB   = validatecolor(color)
ans   = 0.5000   0.0000   1.0000
  • uint8 triplets:
>> color = uint8([127 0 255)]); % uint8 code for 'indigo'
>> RGB   = validatecolor(color)
ans   = 0.4980   0.0000   1.0000
  • uint16 triplets:
>> color = uint16([32768 0 65535)]); % uint16 code for 'indigo'
>> RGB   = validatecolor(color);
ans   = 0.5000   0.0000   1.0000
  • hexadecimals:
>> color = {'#8000FF'}; % hexadecimal code for 'indigo'
>> RGB   = validatecolor(color);
ans   = 0.4980   0.0000   1.0000
  • CMYK (cyan, magenta, yellow, black) quadruplets: not supported by Matlab

Named colors in english, dutch, german and spanish

We have created a functions in biofysica\utilities\colors for more RGB colors by their names in english, dutch, german and spanish:

  • <RGBcolors> for english names
  • <RGBkleuren> for dutch names
  • <RGBfarben> for german names
  • <RGBcolores> for spanish names

A few examples: 

>>colores.AZUL_CLARO
ans = 0.5000   0.5000   1.0000

>>kleuren.FELROZE
ans = 1.0000   0.0000   0.5000

>>farben.BLAU
ans = 0.0000   0.0000   1.0000

>>colors.LIME
ans = 0.0000   1.0000   0.0000


All the named colors are:

RGB Code Hex Code English Name Nederlandse Naam Deutsche Name Nombre en Español Kleur
[0.00, 1.00, 0.00] #00FF00 Lime Limoen Limettengrün Lima
[1.00, 0.00, 0.00] #FF0000 Red Rood Rot Rojo
[0.00, 0.00, 1.00] #0000FF Blue Blauw Blau Azul
[0.00, 1.00, 1.00] #00FFFF Cyan Cyaan Cyan Cian
[1.00, 0.00, 1.00] #FF00FF Magenta Magenta Magenta Magenta
[1.00, 1.00, 0.00] #FFFF00 Yellow Geel Gelb Amarillo
[0.00, 0.00, 0.00] #000000 Black Zwart Schwarz Negro
[0.50, 0.50, 0.50] #808080 Grey Grijs Grau Gris
[1.00, 1.00, 1.00] #FFFFFF White Wit Weiß Blanco
[0.50, 0.00, 0.00] #800000 Maroon Kastanjebruin Kastanienbraun Granate
[0.00, 0.50, 0.00] #008000 Green Groen Grün Verde
[0.00, 0.00, 0.50] #000080 Navy Blue Marineblauw Marineblau Azul Marino
[0.00, 0.50, 0.50] #008080 Olive Olijf Olive Oliva
[0.50, 0.00, 0.50] #800080 Purple Paars Lila Morado
[0.50, 0.50, 0.00] #808000 Teal Zeegroen Türkis Verde azulado
[0.50, 0.00, 1.00] #8000FF Indigo Indigo Indigo Índigo
[0.50, 1.00, 0.00] #80FF00 Chartreuse Chartreuse Chartreuse Chartreuse
[0.00, 0.50, 1.00] #0080FF Royal Blue Koningsblauw Königsblau Azul Real
[1.00, 0.00, 0.50] #FF0080 Hot Pink Felroze Knallrosa Rosa Brilliante
[1.00, 0.50, 0.00] #FF8000 Orange Oranje Orange Naranja
[0.00, 1.00, 0.50] #00FF80 Spring Green Lentegroen Frühlingsgrün Verde Primavera
[0.50, 0.50, 1.00] #8080FF Light Blue Lichtblauw Hellblau Azul Claro
[0.50, 1.00, 0.50] #80FF80 Light Green Lichtgroen Hellgrün Verde Claro
[1.00, 0.50, 0.50] #FF8080 Salmon Zalmroze Lachs Salmón
[0.50, 1.00, 1.00] #80FFFF Aquamarine Aquamarijn Aquamarin Aguamarina
[1.00, 0.50, 1.00] #FF80FF Orchid Orchidee Orchidee Orquídea
[1.00, 1.00, 0.50] #FFFF80 Light Yellow Lichtgeel Hellgelb Amarillo Claro

Color maps

Color maps are used for plots like surface plots. Color maps are arrays with any number of columns and RGB values for every row.
There are 18 predefined color maps in Matlab with 256 colors each. These maps are accessible by <predefinedColormaps>.

  • The default colormap is 'perula'.
myMap = predefinedColormaps.summer;
colormap(myMap)
surf(peaks); %make a surface plot with 'summer' colors.

You can view the color map by creating an instance of predefinedColormaps and call the method show: 

maps = predefinedColormaps;
maps.show(perula);

When you want to see the current active colormap you can use: maps.show(colormap);


You can also define you own maps 

mymap = [RGBcolors.LIME;...
         RGBcolors.RED;...
         RGBcolors.BLUE];
colormap(mymap);
surf(peaks);

All MATLAB predefined color maps:

Name Description
parula A smooth, perceptually uniform colormap with blue-to-yellow transitions, default in MATLAB since version R2014b.
turbo A vibrant, perceptually uniform colormap with a wide dynamic range, transitioning from blue to red via green and yellow.
hsv A circular colormap representing the hue component in the HSV color space, cycling through the full range of colors.
hot A colormap with transitions from black to red, then yellow, and finally white, typically used for thermal or intensity data.
cool A simple linear colormap that transitions smoothly from cyan to magenta, often used for contrast with warm color schemes.
spring A pastel colormap transitioning from magenta to yellow, often used to represent seasonal or thematic data.
summer A light green to yellow colormap that gives a warm, sunny feel, used for representing continuous data.
autumn A colormap with warm tones transitioning from red to yellow, evoking the colors of autumn leaves.
winter A cool colormap transitioning from blue to green, commonly used to represent water or icy conditions.
gray A simple grayscale colormap, transitioning linearly from black to white, often used in intensity maps.
bone A colormap with a grayscale base, but with a slight blue tint, designed for displaying images of bones and x-rays.
copper A colormap transitioning from black to copper-brown, useful for visualizing data with metallic or heat-related themes.
pink A pastel colormap with a gradient from dark to light pink, often used for softer data visualizations.
lines A colormap with distinct, evenly spaced colors, designed for line plots with many different lines.
jet A rainbow colormap transitioning from blue to red, previously the default in MATLAB, but criticized for non-uniform perceptual changes.
colorcube A discrete colormap that uses a fixed set of distinct colors, typically used for categorical or label-based data.
prism A repeating sequence of vivid colors, often used for periodic or cyclic data.
flag An alternating red, white, blue, and black colormap, often used for data with binary or oscillating patterns.

Extra in biofysica\utilities\colors defined colormaps:

Name Description
blueshades A colormap with a gradient from dark to saturated blue.
redshades A colormap with a gradient from dark to saturated red.
greenshades A colormap with a gradient from dark to saturated green.
cyanshades A colormap with a gradient from dark to saturated cyan.
magentashades A colormap with a gradient from dark to saturated magenta.
yellowshades A colormap with a gradient from dark to saturated yellow.
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