Most people won't know they have it,because as mentioned it isn't even mentioned online including the manufacturer's own website!You'd have to actually have a bag and look at it to see the ingredient in the additives section and even then specific information on what colourants are used isn't specified unless you contact the manufacturer
Unfortunately,this does mean the current standard food really isn't as good as it seems.
The positive side to that issue is that there are still alternatives,in the US this would generally mean a Higgins combination diet(Higgins and Mazuri or Carefresh)and in the UK it would either require a food that's slightly low in protein getting boosted or a mixed diet with boosted protein(or Burgess' regular hamster harvest,unless that ends up having hidden dyes).