Might make a difference if she explained why or gave more details. Superficially, it does not make sense, as many curt statements do not... BUT...
I am guessing that, perhaps, what she wanted to say by this statement is that if one conducts an experiment, wherein the same amount of good quality food is fed in two sittings in two days or in one sitting in two days, the colors may come out better, faster with rarer feedings. Digestion is a tricky thing. I can (without any knowledge) speculate that the assimilation of pigments is a slower (different) process than the assimilation of other nutrients, e.g., because pigments are not broken down but absorbed as is. With everyday feedings, the food may be pushed through the tract a bit faster than with 1-in-2-days feedings, and the fish absorbs less and excretes relatively more pigments.
Sorry, this is a lot of water on the proverbial wheel and blah-blah-blah but I guess what I am trying to say is that one would be prudent to not dismiss the words of others right away without attempting to understand what they want to state and why.
As stated, the food must contain pigments in the right amount to be utilized by fish.
Moreover and on a slightly different angle, the main problem with sub-adult and adult RTCs is overfeeding which gives rise to digestion problems and deaths. On that note, one may feed everyday and not overfeed and one may feed once in two days and overfeed. The quantity is completely omitted from the OP and the discussion while it is crucial to it.
