[Help needed] Pick theme and color for the marketplace

[D4N]

Once we upload the extension to the marketplace, we have to pick a color for the main banner and a theme.

For the color, we can pick any color that we like from the RGB spectrum. There are only two themes available, dark and light, which influence whether the displayed font is black or white. E.g. the Open Build Service Connector uses the light theme whereas the VSCode Python extension uses the dark theme.

I guess the main color should be the EOS blue (#ccd1ff) and probably the dark theme?