Font Canvas color change not updating alpha

[pecoram]

I am encountering an issue with font color changes on the canvas text renderer.
When changing the color from 0xffffffff to 0x000000ff, the change is applied correctly. However, (for example) when I try to change from 0xffffffb3 to 0x000000ff, while the color updates, the alpha remains at b3.
The alpha value should go from b3 to ff.

with canvas font

with msdf font