I had mine done about 30 years ago when DH & I decamped to a heath farm for a few days while our kitchen floor was being laid. It was one of the ways they kept the inmates entertained in the evenings, you had to pay extra of course. This was by Colour Me Beautiful.
I was told that I was a Spring & used their colour swatch for years, although being of a rather "oh, that'll do disposition" I wasn't too careful about the shades, just sticking more or less to the colours.
I have recently had my colours re-done by House of Colour & am a Paint Box Spring, which is about as bright as you can get I think. So basically, I think the colours stay with you all your life & at 68 I still have very little grey hair but think that skin tone & eye colour may have faded a bit, it was all much as expected.
Being "in my prime" in the 60s/early 70s I was very much wedded still, to emphasis on the eyes not lips & must say that reversing that has made a big difference.
If you want to dip your toe in the water I very much recommend the blog post on the Kettlewell site.
www.kettlewellcolours.co.uk/blog