Welcome to the forum Marcia, 'cos I don't think I've seen your work before
Well done with the shape - it has a nice 'wild' rose feel to it.
The colours also are good!
The problem is one of tone - so it won't take much!
I think you need (in future paintings) to go extremely lightly on the lightest parts first - barely and colour so you are retaining the light in the petals (which need to be delicate) - and then gradually build tone towards the deepest part of each petal as well as the flower centre. As cjorgensen suggests, it's a matter o playing light against darks to get the contrast.
It's already working on the right/central area
Hope this helps!
BTW - what's the size? ........ and, if you make your image size 500 pixels wide, you'll give the rest of us a better view for commenting