I got stretch marks all over my belly when pregnant with DD. Before DS came along they changed to the same colour as my skin and were not very noticable. Then when i was heavily pregnant with DS the old stretchmarks turned purple and i only got a few new red ones. About a year after i had him they turned back to being the same colour as my skin. Now i am pregnant again with a belly they have turned purple again! I havent gotten any new ones but why do they keep turning purple during pregnancy?