DOS should be yellow or orange, not reddish. Did you make your soap hot process? I also suspect that its your scent that didn't get mixed in properly.
Does it pass the zap test? Do the spots smell bad at all? If its just the scent then yes, its safe to use.
Based on that, I would also say scent - vanilla can discolour the soap (usually brown) and, someone please correct me if I am wrong, DOS is usually a surface thing
Yes EG, you're correct, DOS is a surface thing. I would try mixing the FO in with the oils before adding the lye, and mixing it in well. See if that makes a difference.
They don't look like DOS to me either. They are more likely to be caused by vanilla based scents(or any dark colored FOs) and natural colorants which did not mix well with the soap mixture, especially when you add them at a thick trace.
I have some similar spots, mine are reddish- orange... I was thinking they are DOS, they came up on some bars that belong to a batch that starts to get small dark orange spots here and there...