I dont know whether this will help because I dont know the color of the Ikea piece but the easiest explanation of the TOTO colors is as follows. The Cotton white is a true bright white maybe even gray undertones while the colonial white is off white to cream in color.

I was just looking at those samples the other day. They are very similar but colonial white is just a bit brighter. I would consider it a bright, pure white. Cotton white is the standard color most places stock so that is what you see in the showroom models. The sales rep was trying to convince me that no one ever orders anything besides cotton white but with white wainscoting behind the toilet I want to make sure I get the right white. Plus they are the same price so there is no reason to not the color you want! That's interesting to hear about matching the Kohler products. I can't see them side by side because any showroom that carries Kohler products isn't able to sell Toto products. So I guess I need to check out the sample colors to compare.

I just went through this whole "shades of white" thing - I ordered a Toto cotton white tub and toilet, and a Porcher Sapho sink. Porcher is owned by American Standard, and this sink is also a creamier white than the very bright Toto white. (I don't know if it's as creamy as AS white.) It freaked me out for a while and almost made me not buy the sink, but finally (with the help of my good friends here), I decided it didn't matter and it would all blend in. The light hits things at different angles and makes them look different anyway, and I think your eye will just read everything as white.

dahoov2: "So seeing as they are building me a new bathroom and it'll be an addition and not something adapted, I guess I can get a skirted toilet. I like the idea of dual flush too. I never even heard about "sanigloss" till today as well. "Anything else to look for?" If you are building a bathroom from scratch, definitely -- I cannot emphasize this strongly enough -- make sure that it has a grounded electrical outlet within a foot or two of the toilet at baseboard level. WHEN (it is not a matter of "if") you find that you can no longer live without an advanced toilet seat (also known as a bidet seat or Washlet -- but Washlet is a trademark of Toto so other makers cannot use that word to designate their product), your cost of installation will be significantly reduced if the electrical outlet is readily available. In the meantime, you can have one of the electrical outlets with built-in sensor night-lights installed, which will enhance nighttime visits to the loo. The inevitability that you will be getting an advanced toilet seat also may influence your choice of toilet itself. Almost all Japanese advanced toilet seats will fit right on almost all Japanese toilets (savvy standardization of dimensions), but you'll have a hard time fitting an advanced toilet seat on a square-front Duravit, for instance. https://www.houzz.com/products/duravit-vero-1-piece-toilet-alpine-white-2103010005-prvw-vr~15698952-Vero-1-Piece-Toilet-Alpine-White-2103010005-contemporary-toilets Everyone who has been exposed to the use of advanced toilet seats for more than a few days (many for much shorter periods of time) completely falls in love with the concept. Once you have yours, you will find yourself disquieted when you travel and visit most American hotels and have to do without the amenity. But you can always travel to Japan, where approximately 100 percent of hotel rooms and better than 70 percent of private residences (nearly 100 percent of newly constructed private residences) have advanced toilet seats on every toilet. There are probably more advanced toilet seats in use in Japan now than TV remote controls, and the remarkable thing is that the product category is only about three decades old. We have a Toto Vespin II with an Inax Clessence advanced toilet seat; we chose those two units after much research, and because we travel at least twice a year to Japan (many relatives), and could ask real people real questions about their real opinions. We have recommended the same combination to several friends in America, who have followed our recommendation, and have been delighted with the outcome. Here is a link that might be useful: Inax Clessence