I wouldn't have sanded it like that exactly. Just lightly after a good wash off is enough for it to take a stain .
If you lick your finger and can wet a dry bit and it soaks it in its going to take a stain . Get a rag with some water and do some small tests where you think its good and where you think its bad .
Those parts a few mm above where the side meets the base look like they still have colour . A cabinet scraper can clean that up good . But do a small water test there and see what happens between the raw sanded part and where there still may be finish .