RGB-triangle.svg

Nice triangle! I think it'll look even better (and it'll interact with subsequent filter operations such as feColorMatrix better) if you add to the style:

linearGradient { color-interpolation: linearRGB; }

@donhatch Now that I look at it again I think it actually needs some fixing. The rotations of gradients don't work as I expected.

As for your suggestion, it's quite possible that it will look better. But I think the purpose of this triangle was to be linear in the numbers, e.g. to have the color (255/3, 255/3, 255/3) in the center, which works with sRGB I guess (?).

"(?)" is right! I do not claim to understand what it's thinking-- multiple spooky layers of gamma correction and anticorrection everywhere, I suppose. But you're right, in the end sRGB seems to make it come out with #555555 in the center (and e.g. #800080 in the middle of the magenta edge), which seems like what we want, whereas linearRGB seems to make them come out gamma-adjusted to be somewhat brighter than that in the end.

I have at least fixed the gradients.