Can't change the background color of a WebToolbar at runtime

Hi,

using Xojo 2019 R3, I try to change the background color of a WebToolbar by setting the style to a different one. Thing is the background color is not changed. The only change of appearance is that that at the bottom of the WebToolbar the line which is of a different color - where does that line come from ? - is a little bit thicker.

I had a look into documentation, nothing tell that it’s not possible

I run Xojo on Windows 10, and get the same result on Chrome or Edge DEV version. Another developer gets the same result on Catalina, so it does not seem to be OS related.

Someone has an explanation ?

Thanks