Anyway Rollbit is open for suggestions thus if the gambler raise this feedback to them they will certainly do something to improve it in the future.
Only if a handful amount of people actually complaint about this but for some reason this is probably the first time that someone actually complain about the layout / colour scheme of the site. It doesnt and wont really affect anything while you gamble on the site so I kinda doubt that Rollbit will do something about it even if he raises his concern onto them
They wouldn't care at all yet Rollbit had gained up their popularity and relevance on this market with their own color style or overall interface design, this is why having those small number complaints wont really be a bothersome.