For example, I'd like blue to be a little bit lighter, or change red to be a bit more orangeish. Is this possible?
I know that I can change the background and foreground colors easily. What about the other colors?
As you know, one can easily change the PowerShell console colours using something like this in your profile:
However, you are limited to the standard 16 ANSI colours. You may be able to alter the colours used as the defaults in the registry (I can vaguely remember doing so in the past, but I cannot find any notes on it), but an easy way to do it would be to wrap the PowerShell console with Console2 and use the options in its settings. You'd also get other benefits, like tabs and easy pasting.
EDIT: I just remembered that you can do the same without using Console2. In the standard PowerShell console, just go to the Colour tab in Properties and modify the RGB values of the standard 16 ANSI colours.