[Peter57]

what gives tannic acid its colour? is it possible to remove the colour by mixing it as a solution and distilling?

[Arkcon]

Tannic acid is available as a reasonably pure substance.  Its brown.  You can't purify away any impurities and change its color.  Mixing a solution won't purify it or change its color.  Distilling a powdered organic compound isn't possible.  And mixing, then distilling is also a process that doesn't purify anything.

[Peter57]

Ok, thanks,

is it possible to synthesise low molecular weight tannic acid from the raw stuff?

[arthur1972]

what gives tannic acid its colour? is it possible to remove the colour by mixing it as a solution and distilling?

I also bought 5 drums tannic acid from one China tannic acid factory http://www.tnjchem.com/buy-tannic-acid-tannin-from-china-suppliers-at-best-price_p2327.html and found the same problem. Their explanation is that tannic acid is easy to absorb moisture, easy to oxidize in the air, and the color deepens after oxidation. I checked some  books and says the same.