It's very true, but many online vendors have good return policies, so there's nothing to fear in buying a low color so you can see it in person. It's not easy to find well cut low colors in local stores - antique cuts, yes, if you find a good dealer you can see them in person, but modern RB's and other shapes are harder to find and you may have to buy online to get a good specimen.
I believe the L in question is through a vendor I know to have a good return policy. Double check, but if that's the case, I say go for it so that you can see the ring in person. If you're not in love, send it back and try again.
A dealer (or maybe he was a cutter?) on PS once posted that he routinely sets loose stones in front of buyers, unmarked, in a range of colors. He then asks them to identify the one that's prettiest to their eye. 9/10 times they choose a lower color. But they have a hard time buying the lower color they like because they have been conditioned to think colorless is better. Personally, I feel they are all beautiful! But I really get feisty when people insist that one color is superior to another (not that anyone here has done that, I just mean in general).
All I ask is that people buy what's beautiful to them. For some, colorless is more beautiful and for others, nothing beats a nicely cut M. It's very personal.
One tangent: when I got my L asscher I showed it to several friends. Every one of them said something along the lines of: "It must be a really high quality stone because the color is so pretty. Why don't all diamonds look like this? Why is it so colorful?" and the answer is the L color and that the stone is cut to ideal asscher proportions. I then point out that it's a low color and the reaction is usually, "Oh, so it's not a good diamond?" yet I can see the doubt written on their faces because their eyes are telling them it's beautiful, but they are conditioned to think whiter is better.
If it was a D color, it would perform differently and appeal to different tastes. Is a D more rare? In nature, yes. But what about what you see in circulation every day? I say a beautifully cut L is rarer in day-to-day life than D-F stones. This is a reflection of demand, but doesn't change the fact that an L will be more rare and is perceived by most to be as beautiful as any higher color stone. But you gotta love the look, the body color/tint, etc.
Funny how as we get a little older our tastes keep changing. So this new ring with a matching band would be a drastic change (improvement)...
I couldn't agree more.