colors-transition.js

precalculateColorTransition = function(fromHex, toHex, steps=30) {

	const fromRGB = [	parseInt(fromHex.substr(0, 2), 16),
					parseInt(fromHex.substr(2, 2), 16),
					parseInt(fromHex.substr(4, 2), 16)
				];

	const toRGB = [	parseInt(toHex.substr(0, 2), 16),
					parseInt(toHex.substr(2, 2), 16),
					parseInt(toHex.substr(4, 2), 16)
				];

	let transition = [];
	let transitionSteps = [ (toRGB[0]-fromRGB[0]) / (steps-1),
							(toRGB[1]-fromRGB[1]) / (steps-1),
							(toRGB[2]-fromRGB[2]) / (steps-1)
							];

	console.log(transitionSteps);

	for(let i=0; i<steps; i++) {

		transition.push( 
				parseInt(fromRGB[0] + Math.min(255,Math.ceil(transitionSteps[0]*i))).toString(16) +
				parseInt(fromRGB[1] + Math.min(255,Math.ceil(transitionSteps[1]*i))).toString(16) +
				parseInt(fromRGB[2] + Math.min(255,Math.ceil(transitionSteps[2]*i))).toString(16)
			
		)
	}

	return transition;

}