H color in a well made diamond will be fine, in plat or white gold.
Check out the "Show Me the Ring" portion of the Forum. There are pics there of H, I, and J colored center diamonds, many with higher colored side stones.
First off, H will be more than fine for a platinum setting as long as the stone is cut well. We have seen some exceptional H's and I have an H Regent that is very white!
Secondly....a side note that buying a G instead of an H will not make the stone 'clearer'...but rather it will just be one color grade better. Clarity is more in alignment when discussing inclusions...in essence the color grade at a G or H level has nothing to do with that.
H color is about the limit for platinum. White gold, maybe, but G-H in platinum can have a pretty detectable tint depending on light( and the setting and shape as well as cut). You might want to look at some similar mounted rings to decide if you are comfortable with the amount of tint before you make a permanent decision.
At that point, some customers are happy and some aren't - it's just a personal choice.
Griffin, I'm afraid I have to disagree. Customers here have put well-cut I and J stones in platinum without a problem.
I know there are a few folks who are extremely color sensitive, but for the greatest bulk of people, H will face up just fine in platinum. I own an H, and it faces WHITE.
Dunmore, if the stone is graded by a reputable, accurate lab (like AGS, GIA, HRD), and if it is a well-cut stone, your H will face up beautifully in platinum.
H is the lowest I would recommend,when mounting in white metals.As far as the side stones are concerned a good Jlr. should only match the same color as the center stone, with a slight variation allowed being on the borded of g-h.
From what I've seen, H color can be absolutely okay. It can also look slightly tinted if the H color was assigned by either a liberal lab or a liberal grader.
Case in point: While shopping for stones, my boyfriend and I looked at a 1 ct. ideal cut EGL USA certified H SI2. A tad too yellow.
What did we end up buying? A GIA certified I SI1 (no flour.), which I had guessed was a G. It certainly looked whiter than the H -- in fact, I could barely tell a color difference between the GIA I color and an EGL F color when they were side-by-side.
I'd just second the opinions of others who recommend sticking to a dependably stringent lab like GIA or AGS. This is not to say that EGL is necessarily an evil demon (because they aren't) but in my LIMITED experience I've found their color grading to be a tad bit liberal.
However, if you decide to go with EGL USA, you could move up to G color and higher, and you'd probably be safe.
I'd put my GIA I in platinum for sure. The EGL H I saw, probably not.
H should be great in a WELL CUT stone. Shoot for one of these, I would personally be very happy with a well cut H! Even an I or J.
If you pick a lousy cut you may end up with more colour than you want... Just saw some lousy H stones at the mall - check them out, you will see what I mean.