Colors appear different on Mac vs PC PowerPoint
Problem
You have a set of color standards that you want to use for your slides. You specify the colors as RGB but notice that when you look at your slides in PowerPoint Mac, the colors aren't quite right. And sometimes shapes that should have the same color actually appear slightly different.
Solution
Unlike Windows versions of PowerPoint, PowerPoint Mac displays shape fills differently depending on the type of shape and the system color profile you've chosen (or that OSX has chosen for you).
For example, on a newly reformatted Mac, in PowerPoint 2011 I added a rectangle and filled it with RGB 0,0, 255.
Then, while the rectangle was still selected, I typed some text within the rectangle and gave it the same color.
DigitalColor Meter (a Mac screen color-picker) tells me that the text is RGB 0,0,255 but the rectangle fill is RGB 49, 0, 251.
Why?
Color profiles. Lunatic ones, in my opinion, but perhaps Apple has its reasons. Our problem is not to understand why, our problem is to make the profile die. Or at least quit messing up our colors.
So go to System Settings | Display | Colors. There you'll see the current display profile.
In my case it's "SyncMaster" (my monitor is a Samsung SyncMaster, so this seems reasonable enough). Yours will probably be something else.
In my case, SynchMaster is the only available profile at first, but after I remove the check next to "Show profiles for this display only" I get a few other profiles to choose from.
When I choose the "Generic RGB Profile" the Mac displays the actual color I requested. For both text and shape fill. What. A. Concept!
But the problem with this is ...
This works beautifully on your own Mac but doesn't do you much good if you're creating presentations that'll be played back on a different computer. Or creating them on a PC and praying that they'll be ok when viewed on a Mac.
Jan Schultink has a more complicated but more universal solution. Basically, if you put a thin outline around each bit of text, the text will appear in the correct color (or at least, the same color as other shapes of the same color).