This image shows the same button in 2 different browsers,
first is Brave, the other is FF (which looks the same as Chrome).
The CSS for this is
background-color: rgba(32, 132, 240, 0.5); }
Obviously, the color is far off.
(have to admit, saving the image as jpg exaggerated the purple color a little bit… )
Version 0.18.36 , ubuntu.