Reply To: Unintentional colour shifting

What you're overlooking is this: you are selecting a color in RGB mode, but the document itself is set to CMYK mode. Now InDesign doesn't want you to look surprised when the color you selected doesn't come out of the printer the same (printers cannot print full bright green, for example), so it dims the color on-screen to mimick what it will look like.

If your document is to be printed, make sure it's set to CMYK mode (that's under “Edit -> Transparency Blend Space”, for some reason) and don't expect all of your screen colors to look the same. For Best Results, don't select RGB colors either, but mix them in CMYK.

If your document is going to be screen-only (PDF for on-screen, or web, or SWF, or iStuff), change the blend space to RGB.