I don't know what you mean by turning up on normal ad pages; I think it can only apply to link units. If you mean the message displays even when you're creating an ad unit - I think it's just part of the page, regardless.

So if you have a link unit with a black background and yellow and red colors for the text, your second page (with all the ads) is going to look like that too (if you check that box) You should take a look at it, because some color schemes work better small than large.

This is happening to me too (I already posted about it days ago). It shoul appear only in link units.

Are yoy having trouble with changing colours o visualizing the colours preview?

I've seen several threads on the Adsense forum reporting this, but it seems is not global and it's impossible to hear something from an Adsense advisor.

Sigh

yeah im getting that too. if you go into an existing ad the preview doesnt show, and the color box doesn't match the hex value. it just shows the defaults