They told me as long as nails clear so can see then ok .. they attach something to your finger to monitor and need to see under nail.. so i just had clear. Fake tan defo the worst .. but u dont want it on wen your not gona be able to wash n scrub it off, n if goes in incision wen sweating can cause infection. I started using st tropez shower tan on day 7 wen could shower.. its better thsn nothing at all lol x