You need to change the type-ins. If just type, White, Black and Brown, I get 100%. Either accept just the first name or require the whole name, but accepting just the last name is not very challenging.
Oh yeah. Good point....but you know what? Lifes too short....if people wanna just put the surnames in then you'd have to question how they spend their time, and thats more than mine for making such a quiz and yours for the above comment.