To answer about color, let me start off with this. We have had these pictures off and on in listings to help show how certain yellows will look set. I just cropped them up and put them side by side so they would fit on a page easily.
Also wanted to show these...
First a glamor shot of Sunny so you can see a photo David took of her since the ones below are mine - well one obviously isn't but you know. I was blown away with how deep yellow she looked when I got the photo
and now my own photos next to David's stock photo
This is Sunny (yep that's my diamond's name) loose, set in a simple solitaire (had no clue what I wanted so she stayed that way for a year) and then now in the double bezel. Even my bezel which isn't designed the same way that the beautiful halo ring that OMC posted, does give off a good amount of help with the yellow.
What I really love about my ring is that in some lighting, my diamond blends with the color of the 18K Yellow Gold metal and looks *massive* Other times it obviously is a very vibrant yellow that really does look closer to a Fancy Color. I've had three jewelers ask me if it was a Fancy Yellow even next to other Fancy Yellows (one was Tiffany and two local jewelers - one who was cleaning it for me and the other was fixing some old earrings I bought from them ages ago - pre DBL as I call it). So these lighter yellows are fascinating to me because they do have a range they look depending on the lighting.
The good thing about the single bezel is that it has a lot of yellow gold in the mounting around the stone to help the color as well. Even more so than my bezel.
I realize I haven't answered yet, but you need to ask yourself what shade of yellow do you want? To go from the size of stones you had to the 1.02ct W-X would be noticeable. There is absolutely no denying that. You originally said that color was *the* most important to you. I do get the feeling that size is really up there too and there is *nothing* wrong with that. I admit I wanted a certain size or larger (5x5mm was my minimum) and I got lucky that David had Sunny (.93ct for the record). Now in a bezel she's HUGE and I love it...
You have to decide first what color you really would be happy with. When I was looking I wanted S-T and above. I am actually happier with the slightly more yellow. As much as I love FY diamonds I actually really do love the Y-Z and FLY best. That's my *personal* preference. So do you like a softer yellow or that can look very yellow many times or do you want yellow all the time no matter what the lighting?
I will disagree with OMC on the E-W thing though. My double bezel which comes from a stone that is 6.34 x 5.15 mm goes to approximately 9.5 x 8.3 mm. So if a double bezel added about 1.5mm to the stone on either side, I don't think that a single bezel would be more than 1.5mm total so 8mm at the longest which wouldn't be too bad on a 8.5 finger IMO.
I am not sure I could do my stone double bezeled E-W on my finger (sized at about a 4) but I could definitely do a single bezel E-W based on what I wear daily.
Lots of rambles, but hopefully photos will help you decide how yellow you really want. I am a fan of softer shades, but absolutely appreciate and love seeing the more vibrant yellows. For my life and personality the Y-Z is perfect for me