gamut_mapping_xyz_to_srgb called srgb_to_oklab(clipped_r, clipped_b,
clipped_g) when computing the clipped color's delta from the original
during binary search, swapping g and b. The comparison color on the
next line used the correct order, so the JND check was comparing
against the wrong OKLab point and could converge on a less accurate
clipped chroma. .a{color:oklch(0.65 0.3 50)} targeting chrome90 now
lowers to #e56300 instead of #de6800.
