Does such a thing exist?
I once had a moisturiser that was supposed to gradually stain your skin over a week or so, to give you a subtle 'sun-kissed glow' without sudden changes or troublesome streaks. The idea was that once you'd got to the level of tan you liked, you then switched back to your usual moisturiser and only used the staining one every 2-3 days to maintain the colour.
It was a disaster on my face (I looked like I'd eaten too many carrots!) but worked perfectly on my legs. On my legs it gave just a subtle colour, a suggestion that this was not the first time in 12 months that my knees had seen sunshine.
That's the sort of thing I'm after, but it has to be fragrance-free.
Any ideas?