Question

What color do the hottest stars appear to be?

Answer 1

Blue-white, or blue

Explanation:

Stars' heat output affects their colour, as you clearly know, but as they emit across a broad spectrum of frequencies, our eyes only register the hottest as blue. By then they are already emitting much more radiation in the UV than in the visible range.

O, B, A, F, G, K, M is the normal range - see http://www.astronomytrek.com/interesting-facts-about-the-colour-of-stars/