Turquoise veins in my leg?

I'm currently tanning (with spf) and I noticed beside my knee cap and a little down my. Veins are turquoise I thought it might have been a marker however they kinda go up my thigh, they don't stick out its just very odd. I'm medium skin tone do you think this is bad? I've tried google searching and nothing
Turquoise veins in my leg?
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