Do cories prefer dark substrate?

[Chrisk-K]

I have white sand in my tank and my peppers and julii are much more active when the light goes off at night. I wonder if it has something to do with the color of substrate. Do they prefer dark substrate?

[tanker]

Most corys are more active at night.

[pinkertd]

:iagree: The only cories I have that stay right out in the open all the time are my albinos and my black cories. And young cories are always much more active no matter light or dark compared to the older or adult cories.