Changing PM notification colour

[Raid0]

So I go to:

Themes > Theme > global.css > Advanced Edited

Then I find the part of the text that says:

.pm_alert {
background: #FFF6BF;
border: 1px solid #FFD324;
text-align: center;
padding: 5px 20px;
margin-bottom: 15px;
font-size: 11px;

Now how do I edit this? I know I need to change the numbers on border and background, but how do I get the numbers for the colour I want?

[BleepyEvans]

If you have photoshop, you can use the colour wheel to pick the hex colours of your choice.
If not then heres a nice colour picker for you to play with: http://www.w3schools.com/tags/ref_colorpicker.asp