This is part of bug 355727.

Color clamping occurs basically on three different entities:

• serialization: colorToXML and colorFromXML
• math tooling: usage of KoColorSpaceMaths<_T, _Tdst>::scaleToA, and color space properties such as KoColorSpaceMathsTraits::zeroValue and KoColorSpaceMathsTraits::unitValue, most commonly with a qBound to clamp extrema
• Qt facilities: usage of QColor's and the related LCMS transformation in toQColor, which both clamp to 8-bit sRGB.