It shouldn't matter what colour people's faces are, but it does. Try telling anyone who has ever been attacked because they had the wrong colour face that it doesn't matter.
If you don't have any black people on any of your publicity material, it gives a very good idea of where you think black people fit in your party.
Similarly with women, people with disabilities etc.
The lack of inclusion of them, is an indicator that you're not that interested in addressing the specific issues that face them which don't face people who are not women, disabled, black etc. Which means you're either content with their marginalisation in society or you refuse to acknowledge it. So in that context it's absolutely a valid question IMO.