Eastman says yes and that she was based on his then-girlfriend (who was also named April). Laird says if that's the case then he wasn't aware of it.
Her first appearance, in issue #2, has her looking much as she would in her later animated appearances, but starting in #4 and for the duration of the original Mirage run she had curly black hair. Her complexion usually tended toward the tan on the occasions when she appeared in color.
So basically I find it fairly plausible that both creators are telling the truth, that Eastman intended her to be biracial and Laird didn't, and it's hard to say what the "original" intent was when her appearance changed pretty substantially a few issues in.
(It does seem a little odd that Laird wouldn't notice that April had the same name as Eastman's girlfriend and also looked like her. My guess is he knew the name was an homage but didn't know the appearance was -- given that Mirage April also bears a passing resemblance to Julie Strain, it could be that Eastman just has a type.)