Board Thread:Support Requests - Designing Your Wiki/@comment-7706769-20130404231231/@comment-3269579-20130409090839

There are a lot of colours: that 16 million-and-something equals 2563 — I hope you've found something suitable by now 5er4ever? I happened to be online when original post was made, hence the instant response!

As Elecbullet says, aside from using 'named' colours you can specify precise ones using hex notation, where the pairs of letters/numbers affect, in sequence, the red, green and blue balance of your tone, graded from 00 to FF as the intensity increases: e.g. is pure red,  is green and   is blue;   is white (all three 'maxed out') and   is black (all three 'minimised'), and so on.

There's a good few hex-generator websites out there that will produce the exact code for the shade you select, or if you use something like Photoshop and bring up your current 'brush colour' on the colour wheel then that will also tell you its hex code — plus its rgb code, the alternative system mentioned above. You'll see both notations appear alongside each named colour on the page I linked to before, while the likes of http://www.colorschemer.com/online.html allow you to convert between the two for any given shade.

If you're still trying to get just the right tone, the variant on the latter system known as rgba is useful, though not all browsers (particularly older ones) will support it at present; here the "a" stands for 'alpha' and allows you to set the opacity/transparency of your shade as well — to take Elecbullet's example, it would appear as, where the final   means a solid opaque colour, as usual, but if you reduce this figure to say   or   you get progressively more transparent shades that allow the background colour of whatever's behind it to bleed through. I appreciate this isn't so relevant to Theme Designer, but I have used it a little for some small elements on the wiki I admin, e.g. a few backgrounds and shadows for boxes (divs) or table cells. See http://www.css3.info/preview/rgba/ for a more formal explanation of this, and you can try it out at http://www.css3maker.com/css-3-rgba.html, which has sliding bars to choose the décor of your dreams  :)