Downward pointing face on cube discoloured

I'm relatively new to the whole unity thing and have encountered many a problem, all of which have been solvable through persistence and googling, until now. I have come across the issue that the downward point face of my cubes are a dark off coloured orange (When they are supposed to be white).

This is a particular hassle as i'm trying to create a simple room with first person camera interaction which is being ruined by the nasty colour of the ceiling. Basically I need to know if it is possible to stop this (I should very well hope so) and if so how it is done.

Thanks in advance Dave.