[Feature Request] Option to decode colours as multiples of 8

[MarioFanGamer]

The current way of calculating the colours is to divide them by 31 and multiply them by 255 (essentially treating them as fixed point numbers) or take the upper threemost bits and copy them to the lowest three bits. This is fine for accuracy, however, The Spriters Resource prefer if the colours are multiples of 8, like how ZSNES calculates colours, instead of the current accuratacy it has. Being able to switch between both colour modes would thus be very helpful.