your red looks as though its hitting black, which means dark, but the one thing it lacks is the brightness
for example, look at the contrast in your white, it goes from dark grye to bright white, your red however seems to go from dark red to slightly brighter red
so one thing to do is speed up your blending, which just means highligth a bit faster, so for example the raised parts of the folds will go from medium red(near the top of the crease) to a much brighter red near the bottom as it fans out...this is because light hits the fanned out part more because of the angle
blending looks pretty good, the white could be a bit smoother(more glazes) but other than that looks good!
Starks