You need to shift the scroll button up which will make other colors visible (as per my knowledge).
On Mon, Jan 18, 2010 at 1:53 PM, Dave Page <dpage@pgadmin.org> wrote:
Hi Guillaume,
I just went to add a server in a pgAdmin build from SVN trunk and noticed that the new colour selector doesn't work so well on Mac. You can't see easily what the selected colour is - it just looks like a big ugly button. Further, when you click it for the first time, the settings are such that it's far from obvious how to select a colour other than black (actually, you need to set the vertical slider on the right to the top to see solid colours).