>> ... Does the direct-index thing (*v6W[2][3][0][8][8][8]) ONLY work on graphics ...
>> ... have to define every text color before using it if it isn't in the simple color list?
I believe that is the case; for text, you have to select a colour via a palette index, and with palettes with 3 -> 8 bits per index, the default palette has specific colours (Black, Red, Green, Yellow, Blue, Magenta, Cyan, White) defined for indices 0 -> 7, and black for indices > 7.
>> ... I'm doing (*v#S) to set foreground color, and I do *GET* color ...
>> ... but they are FAR from the RGB colors I am expecting
The PCL5 Colour Technical Reference manual describes a number of other sequences (Render Algorithm, User Defined Dither Matrix, Gamma Correction, Color Lookup Tables, Viewing Illuminant) which may affect colour rendition.
I'm not that familiar with any of these, so can't offer any advice as to how much of an effect they would have on your symptoms.