A tinted diamond is a "white" diamond with a bit of tint.  Some diamonds in the J, K, L, M, N, O-P, Q-R range show tint, others can look very white.  S-T is right on the line. It can go looking yellow, it can look just tinted white.

Below is an example of a tinted white diamond. It is an L color. Quite gorgeous but you can see it is not snow white.



Below is an oval that is K color. If a diamond is well cut, it often looks whiter by the way.



The advantage is that you can get a GORGEOUS diamond in a large size for less if it's in these lower color ranges.

This page shows the diamond color from the whitest white, to the most saturated yellow.

http://diamondsbylauren.com/DiamondCOLORchart.shtml

Hey everyone,
Good advice given so far.
A common misunderstanding when it comes to shopping for yellow diamonds.
If someone's never seen a Y-Z, for example, they might assume it's not a "Fancy Colored Diamond"
A lot of jewelers- and others in the biz- have not seen, or don't understand the light fancy colors.
In a lot of cases shoppers have been told  Y-Z, U-V are simply "tinted" as opposed to light fancy colors, as we see them.
As WM pointed out diamonds which are between white, and fancy colors- K-L-M-N....... diamonds of any color can be beautiful when well cut.

A great question.....I'd say Q-R is the last " near colorless" grade.

Oh yes you are right. I would love my avatar in a double baguette setting.