The anchor bolt location for the seat on a Toto is standard to the industry value. The general shape of either the round or elongated bowl is standard. The exact shape of the bowl differs by brand, so a non-OEM seat will fit, but may not match the curves exactly (ie., you may have more or less overlap than the factory seat). Whether this is an issue for you or not is up to you. Same is true with the color matching...each manufacturer's colors can differ slightly. But, you'll also find the perceived color will differ based on the material and the lighting. A few people have noted that the bowl between the two bolts for the seat on some toilets is not perfectly level, and on some seats, this can cause issues. Depends on the seat you are trying to install - 99% of them don't care (and not all toilets have a curve there), but some do. Check yours and then look at the seat you want to ensure you aren't dissappointed. All of the Toto seats, the area around the bolt is like a little pedestal and not continuous between the two bolts, some other brands, the whole hinge point is flat between the two bolts. If the toilet isn't flat there, the seat may need shims or something, or you might not be able to tighten it down.
