It sounds like stretch marks... I always got stretch marks after the baby was born (stretch marks happen with sudden changes in size and I guess my skin is more sensitive to "getting smaller" than it is to "getting bigger"). The color should even out though it might take several months and your belly button should go back more or less to normal as well. You could check out the BAKS basics (tupler technique, it's a "do anywhere" exercise set to close the diastasis recti that forms during pregnancy) but it sounds like normal pp changes to me.
Congrats on your baby!
Congrats on your baby!
