three.js/examples/js/math/ColorConverter.js

( function () {

	var ColorConverter = {
		setHSV: function ( color, h, s, v ) {

			// https://gist.github.com/xpansive/1337890#file-index-js
			h = THREE.MathUtils.euclideanModulo( h, 1 );
			s = THREE.MathUtils.clamp( s, 0, 1 );
			v = THREE.MathUtils.clamp( v, 0, 1 );
			return color.setHSL( h, s * v / ( ( h = ( 2 - s ) * v ) < 1 ? h : 2 - h ), h * 0.5 );

		},
		getHSV: function () {

			var hsl = {};
			return function getHSV( color, target ) {

				if ( target === undefined ) {

					console.warn( 'THREE.ColorConverter: .getHSV() target is now required' );
					target = {
						h: 0,
						s: 0,
						l: 0
					};

				}

				color.getHSL( hsl ); // based on https://gist.github.com/xpansive/1337890#file-index-js

				hsl.s *= hsl.l < 0.5 ? hsl.l : 1 - hsl.l;
				target.h = hsl.h;
				target.s = 2 * hsl.s / ( hsl.l + hsl.s );
				target.v = hsl.l + hsl.s;
				return target;

			};

		}(),
		// where c, m, y, k is between 0 and 1
		setCMYK: function ( color, c, m, y, k ) {

			var r = ( 1 - c ) * ( 1 - k );
			var g = ( 1 - m ) * ( 1 - k );
			var b = ( 1 - y ) * ( 1 - k );
			return color.setRGB( r, g, b );

		},
		getCMYK: function ( color, target ) {

			if ( target === undefined ) {

				console.warn( 'THREE.ColorConverter: .getCMYK() target is now required' );
				target = {
					c: 0,
					m: 0,
					y: 0,
					k: 0
				};

			}

			var r = color.r;
			var g = color.g;
			var b = color.b;
			var k = 1 - Math.max( r, g, b );
			var c = ( 1 - r - k ) / ( 1 - k );
			var m = ( 1 - g - k ) / ( 1 - k );
			var y = ( 1 - b - k ) / ( 1 - k );
			target.c = c;
			target.m = m;
			target.y = y;
			target.k = k;
			return target;

		}
	};

	THREE.ColorConverter = ColorConverter;

} )();