ageneau / colors

Color and colorspace calculation, manipulation and conversion in Clojure.

About

Colors provides color manipulation routines to Clojure. Note that while this project is being used by some folks, it isn’t in very active development. Another more active clojure project working in the same space is:

https://github.com/thi-ng/color

Further references:

• HSL and HSV: http://en.wikipedia.org/wiki/Luminance-Hue-Saturation
• RGB color space: http://en.wikipedia.org/wiki/RGB_color_space
• SASS color module: http://github.com/nex3/haml/blob/master/lib/sass/script/color.rb
• R colorspace package: http://cran.r-project.org/web/packages/colorspace/index.html
• ColorBrewer http://colorbrewer.org/
• R ColorBrewer palettes: http://sekhon.berkeley.edu/library/RColorBrewer/html/ColorBrewer.html

Install

Colors is now up on clojars, so you can add it as a dependency to your lein project like normal:

:dependencies [[com.evocomputing/colors "1.0.6"]
               ...other deps ]]

Example Usage

Create Color Objects

The first point of entry is to create a color object. This package takes a wide range of representations to be passed to the create-color multimethod

(use 'com.evocomputing.colors)

;;Symbolic: Either a string or keyword or symbol that matches an entry
;;in the symbolic color pallete. Currently, this is defaults to the
;;html4 colors map and x11 colors map, but the end user of this library
;;can set any named palette they want.

(create-color "blue")
(create-color :blue)

;;Hexstring: A hex string representation of an RGB(A) color

(create-color "0xFFCCAA")
(create-color "#FFCCAA")
(create-color "Ox80FFFF00") ;; alpha = 128

;; Integer: An integer representation of an RGB(A) color
(create-color 0xFFCCAA) ;; integer in hexidecimal format
(create-color 16764074) ;; same integer in decimal format

;;Sequence or array of RGB(A) integers
(create-color [255 0 0])
(create-color [255 0 0 128]) ;;alpha = 128

;;Map of either RGB (A) kw/values or HSL(A) kw/values
;;Allowable RGB keys: :r :red :g :green :b :blue
;;Allowable HSL keys: :h :hue :s :saturation :l :lightness

(create-color {:r 255 :g 0 :blue 0})
(create-color {:r 255 :g 0 :blue 0 :a 128})
(create-color {:h 120.0 :s 100.0 :l 50.0})
(create-color {:h 120.0 :s 100.0 :l 50.0 :a 128})

Convert colors

You can easily convert color objects into java.awt.Color objects, or a packed 32 bit integer representation, or its component R, G, B, A or H, S, L, A parts.

(use 'com.evocomputing.colors)

(def red-color (create-color :red))
;;Convert to java.awt.Color
(awt-color red-color)

;;get the rgba integer representation
(rgba-int red-color)

;;get the hexstring representation
(rgb-hexstr red-color)

;;get a vector of the constituent rgba components
(:rgba red-color)

;;likewise for the HSL constituent components
(:hsl red-color)

Manipulate colors

You can easily manipulate and adjust colors with simple operations

(use 'com.evocomputing.colors)

(def blue-color (create-color :blue))
;; => "#<color: blue R: 0, G: 0, B: 255, H: 240.00, S: 100.00, L:#50.00, A: 255>"

;;Create new color 1/3 way around color wheel
;;to get new primary red color
(adjust-hue blue-color 120)
;; => "#<color: red R: 255, G: 0, B: 0, H: 0.00, S: 100.00, L: 50.00, A: 255>"

;;lighten by 20%
(lighten blue-color 20)
;; => "#<color: 0xff6666ff R: 102, G: 102, B: 255, H: 240.00, S: 100.00, L: 70.00, A: 255>"

;;darken by 20%
(darken blue-color 20)
;; => "#<color: 0xff000099 R: 0, G: 0, B: 153, H: 240.00, S: 100.00,#L: 30.00, A: 255>"

Color Palettes

You can use the com.evocomputing.colors.palettes package to easily create semantic color palettes. The functions in com.evocomputing.colors.palettes.core follow the functions in the R colorspaces package. http://cran.r-project.org/web/packages/colorspace/index.html

(use 'com.evocomputing.colors)
(use 'com.evocomputing.colors.palettes.core)
(use 'com.evocomputing.colors.palettes.color-brewer)

;;Create a rainbow qualitative palette of 10 colors
;;each with different hues given a single value of each
;;saturation and lightness
(rainbow-hsl 10)

;;Create a diverging palette of 10 colors, composed of a set of colors
;;diverging from a neutral center (grey or white, without color) to two
;;different extreme colors (blue and red by default).
(diverge-hsl 10)

;;Create heat palette in HSL space. By default, it goes from a red to
;;a yellow hue, while simultaneously going to lighter colors (i.e.,
;;increasing lightness) and reducing the amount of color (i.e.,
;;decreasing saturation).
(heat-hsl 10)

;;Create an 8 item ColorBrewer sequential palette "YlOrRd" (Yellow,
;;Orange, Red)
(get-color-brewer-palette "YlOrRd" 8)

Documentation

API Documentation for colors is located at: Colors API

Thanks

I all but abandoned this project after 2010 or so. I’d like to thank everyone who have furthered the work on this project by submitting patches. James Elliott deserves a special shout out for all the work he’s done. Check out his afterglow project to see a really cool project that uses colors to great effect.