"A transparent tube of tone shifting goo. The label has 'CoverItAll Foundation' in bold and bright pink font, the subtitle offers a promise of coverage on blemishes and other unsightly marks. The back is full of chemical warnings you would rather not read. It has a X of goo left."
And for skill rolls on it. :-P
Bad disguise roll: 'Messy splotches cover a clear tattoo/bruise. You can make out "..(randomly selected text 10-20 character long)..".'
Moderate disguise roll: 'You notice %N's skin tone is slightly discolored on %p (bodypart).'
Good disguise roll: Nothing!!!