Yeah, I've also been taking advantage of this bug, place 1 blue gleam and 49 white gleam in and get 50 blue refined gleam out, or 50 blue lanterns out. Trouble is I am not sure how if would effect things like making a block of stone if you had 30 from Therka and 20 from Nasharil, or a mass crafting storage units if they took out. I guess it's only a problem with rare blocks.
On the topic of dyes I'd adore some sort of dye system for clothing/character customisation in the future. Also I'd love to see dye being made from recipes and used in more crafting, imagine different coloured materials used in furniture or carpets, or wall hangings.
(I won't lie I was putting the red leaves in different machines with the white stones and trying to work out how to dye the block red when I first started :))
However I think it should be way down the line, I'd rather see the more complicated core mechanics in the game and tested out first before the fluff.