Personally I don’t like the idea of coloured paints just to change the colours of blocks and such - we have potentially 256 different colour variations of blocks which could be available, requiring you to advance to harder worlds to collect them. There would be no real reason imo to then colour those blocks a different colour.
I think dyes and such will come more into play when we start getting into wearables - or possibly even for the stickers concept that was being explored by Minyi.