const hexToDecS = "0123456789ABCDEF";
const hexToDecI = (c: string): number =>
    c
        .split("")
        .reverse()
        .reduce(
            (acc: number, c: string, i: number) => Math.pow(16, i) * hexToDecS.indexOf(c.toUpperCase()) + acc,
            0
        );

const isHex = new RegExp("^[0-9a-fA-F][0-9a-fA-F]?$");
export const hexToDec = (r: string, g: string, b: string) => {
    if (!(r.match(isHex) && g.match(isHex) && b.match(isHex))) {
        console.error("hexToDec passed an unrecognizable number.");
        return null;
    }
    return [hexToDecI(r), hexToDecI(g), hexToDecI(b)];
};