Hi Pandora, good thing your question isn't as bad as opening the famous box with all the ills of the world!
As CrisW said spelling is important and that's why we encourage all quizmakers to structure their quizzes without fill in the blank answers unless they are perfectly clear.
Many people don't understand this, but we've learned it by trial and error in our own work and editing.
In the past we accepted more quizzes with this sort of thing in it, and you might be taking some of those. Now however we are trying to guide people to making quizzes that are more foolproof.
I keep telling people that if they themselves took their own quiz and got an answer wrong then they'd feel bad. Especially on their favorite subject.
They often try to put the wrong spelling in then.
But we don't allow this here.
The only time would be "watercolor" and "watercolour", American and British spellings.
And even then it would be better to avoid it.
Good luck.