You could use the word, Red, for Scarlet is really a red. Of course, it'd be a bit lame if you wrote about a 'red' woman rather than a 'scarlet' woman. Then again, if you said that the Communists were scarlet rather than red, that, too, would not be the right word.
If you think I'm padding this out your are right, for I cannot think up another word to describe scarlet other than red. Rosy, maybe? Rosy seems to indicate a reddish colour even though roses might be white, yellow, pink (and red is a sort of pink with more white mixed in, as in a pink paint)
A deep blush? Red rather than scarlet...but if you're willing to stretch a long bow...
What sort of question is this anyway?