Incorrect .svg colorization by MultiEffect

When Multieffect.colorization is applied to svg images that are filled with any other color but white, colorizationColor does not replace the original color of the image: it rather blends in or doesn't apply at all.

Problem is discussed more widely here:

https://forum.qt.io/topic/144070/qt6-color-svg-using-multieffect

Current solution is to apply brightness: 1.0, but it seems to be undocumented like the issue itself.

Example is attached.