Thanks. I realize it would require an LCL widget tweak. I did not realize that TColor used the high byte for system colors, making it a bit more complicated.
It is a wish list item, and not critical. My applications allows selection of:
fill color
fill opacity
stroke color
stroke opacity
stroke width
Since macOS includes opacity in the color dialog, it would cut down on the required selections. I was not aware that Windows and Linux recently began supporting opacity, I do not see it in the versions I am using. If that is the case, it is a good argument for supporting opacity in TColorDialog.
I mainly use BGRABitmap display/output and SVG output. I appreciate the BGRAControls project, but am likely to stick with native controls.
Cheers