Color

This class provides many functions for converting color spaces, calculates color differences, scales and much more.

Documentation

Set new color functions

setRGB( r, g, b )

Defines color from parameters red, green and blue [0...255].

setRYB( r, y, b )

Defines color from parameters red, yellow and blue [0...255].

setHEX( hex )

Defines color from hexadecimal notation hex (3 or 6 digits, with or without hash).

setHSL( h, s, l )

Defines color from parameters hue [0...360], saturnation [0...1] and lightness [0...1].

setHSV( h, s, v )

Defines color from parameters hue [0...360], saturnation [0...1] and value [0...1].

setCMYK( c, m, y, k )

Defines color from parameters cyan, magenta, yellow and black key [0...1].

setYUV( y, u, v )

Defines color from luma component y and chrominance components, called u (blue projection) and v (red projection) [0...255].

Output functions

toRGB()

Returns color as [ r, g, b ].

toRYB()

Returns color as [ r, y, b ].

toCMYK()

Returns color as [ c, m, y, k ].

toHEX( hash [ = true ] )

Returns color with hexadecimal notation.

toHSL()

Returns color as [ h, s, l ].

toHSV()

Returns color as [ h, s, v ].

toXYZ()

Returns color as [ x, y, z ].

toYxy()

Returns color as [ Y, x, y ].

toLAB()

Returns color as [ l, a, b ].

toLCH()

Returns color as [ l, c, h ].

toYUV()

Returns color as [ y, u, v ].

toYIQ()

Returns color as [ y, i, q ].

toYCbCr()

Returns color as [ y, Cb, Cr ].

toYPbPr()

Returns color as [ y, Pb, Pr ].

Calculation functions

gamma()

Returns [ r, g, b ] with gamma correction.

deltaE( Color compare, percentage [ = false ] )

Returns ∆E as the difference or distance between two colors (CIE76).

ΔE	Evaluation
0.0...0.5	almost imperceptible
0.5...1.0	noticeable to the trained eye
1.0...2.0	slight color difference
2.0...4.0	perceived color difference
4.0...5.0	significant, rarely tolerated color difference
above 5.0	the difference is evaluated as a different color

diff( Color compare, space [ = 'RGB' ] )

Returns difference or distance between two colors. Accepted color spaces are RGB and RYB.

match( Color compare, space [ = 'RGB' ] )

Returns difference or distance between two colors at percentage value. Accepted color spaces are RGB and RYB.

complementary() or invert()

Returns Color object with complementary color.

rotate( degrees ) or shift( degrees )

Return Color object with color shift (rotation) by degrees [-359...359].

saturation( value )

Return Color object with changed saturation by value [-1...1].

lighten( value )

Return Color object lightened by value [0...1].

darken( value )

Return Color object darkened by value [0...1].

grayscale( correction [ = false ] )

Return value of grayscale. Gamma correction is optional.

toGrayscale( correction [ = false ] )

Return Color object for grayscale color. Gamma correction is optional.

triadic() or triplet()

Return triadic color scheme (three colors that have the same distance from each other in the color wheel).

contrast()

Return contrast of given color: 0 is dark and 1 is light contrast.

gradient( Color stop, steps [ = 1, boundary [ = true ] ] )

Return array of Color objects with colors bewteen itself and stop color. steps form 0 up to 255 allowed, boundary = false returns array without start and stop colors.

palette( type [ = 'tints', steps [ = 1 ] ] )

Return array of Color objects with tints or shades form itself. steps form 0 up to 255 allowed.

nearest( count [ = 1 ] ) or closest( count [ = 1 ] )

Return array of named colors with their Color objects nearest to itself.

Examples

Example 1: Convert color

# define new Color object
$color = new Color();

# set RGB color
$color->setRGB( 136, 176, 75 );

# convert to HEX
print_r( $color->toHEX() );

# convert to CMYK
print_r( $color->toCMYK() );

Output:

#88b04b

Array
(
    [c] => 0.22727272727273
    [m] => 0
    [y] => 0.57386363636364
    [k] => 0.30980392156863
)

Example 2: Distance between colors

# define new Color objects and set colors
$color_1 = ( new Color() )->setHEX( '#34568B' );
$color_2 = ( new Color() )->setHSL( 257, 0.242, 0.471 );

# get ΔE
print_r( $color_1->deltaE( $color_2 ) );

# get color match
print_r( $color_1->match( $color_2 ) );

Output:

16.369734508952

0.87070712531894

Example 3: Generate gradient bewteen two colors

# define new Color objects and set colors
$color_1 = ( new Color() )->setHEX( '#c8dee3' );
$color_2 = ( new Color() )->setRGB( 24, 53, 140 );

# generate gradient with 10 colors
$gradient = $color_1->gradient( $color_2, 10, true );

# output result colors
foreach( $gradient as $i => $color ) {
    
    printf( '[%2d] %s', $i, $color->toHEX() );
    
}

Output:

[ 0] #c8dee3
[ 1] #b8cedb
[ 2] #a8bfd3
[ 3] #98afcb
[ 4] #88a0c3
[ 5] #7891bb
[ 6] #6881b3
[ 7] #5872ab
[ 8] #4863a3
[ 9] #37539b
[10] #284493
[11] #18358c

Example 4: Nearest named colors

# define new Color object and set color
$color = ( new Color() )->setHEX( '#cc9074' );

# find nearest 10 named colors
$nearest = $color->nearest( 10 );

# output result colors
foreach( $nearest as $i => $color ) {
    
    printf( '[%d] %s (#%s)', $i, $color['name'], $color['color']->toHEX() );
    
}

Output:

[0] Antique brass (#cd9575)
[1] Burning Sand (#d99376)
[2] Antique Brass (#c88a65)
[3] Whiskey (#d59a6f)
[4] Copperfield (#da8a67)
[5] Tan (Crayola) (#d99a6c)
[6] Middle red (#e58e73)
[7] Camel (#c19a6b)
[8] Raw sienna (#d68a59)
[9] Dark salmon (#e9967a)