Goldfish are not particularly attracted to any one colour.
if a goldfish is in the dark for a long period of time it will turn gray
It will turn white, or at least will start having some loss of color.
goldfish do
If a goldfish is kept in the dark it will appear lighter in the morning, So if left in the dark for a long period of time, a goldfish will turn almost white. If kept in the light, it will absorb color, and often become a brighter gold. (almost the same as when we tan, the sun gives us color, and when we get less of it we turn whiter, or lighter)
A goldfish left in the dark would gradually, over time, turn completely white. This is because the color pigmentation cells responsible for the fish's bright color, cannot work without sunlight. It would, however, take a very long time for a goldfish to lose 100% of its color because they have so many color pigmentation cells in their scales.
The short answer to this question is 'probably not white, though the color will become much paler'.
the lack of light being in the dark
Yes!
Goldfish can lose their orange color due to light deficiency or dietary deficiencies. In these cases, the color change is often reversible.
It will eventually turn white.
Very dark, all the time, but truthfully it isn't healthy for the goldfish to be subjected to such conditions and it is just plain cruel to force a goldfish to stay in a dark room all the time.
theoretically, yes! a goldfish will loose color if you put it in the dark. Allow the fish to get NON-direct natural sunlight (don't ever place a goldfish in direct sunlight though) and it should return to its natural color within a few weeks to a few months if you feed it properly. you can get color enhancing foods at the pet store, which will help :) proper nutrition and care make for a healthy, colorful fishy friend!
no