[plt-scheme] need DrScheme Check Syntax help

I really like the colorizing in DrScheme, but I'd like even more
colorizing than I get.  There's too much blue uniformity.  If I go to

Preferences -> Check Syntax

then I see that there are 2 blues (rgb = 0 0 128), 

bound variable & primitive.

So I changed the color of primitive to purple, i.e. rgb = 255 0 255.

But I don't see any purple, it's all still blue.

Now according to the PLT DrScheme: Programming Environment Manual:

 * Syntactic Highlighting Keywords, bound variables, unbound variables
   and constants are all highlighted with font and color changes. 

Note `primitive' doesn't occur in this list.  Maybe I don't know what
primitive means.  The PLT MzScheme: Language Manual reads:

 A primitive procedure is a built-in procedure that is implemented in
 low-level language. Not all built-in procedures are primitives, but
 almost all R5RS procedures are primitives, as are most of the
 procedures described in this manual.

 * (primitive? v) returns #t if v is a primitive procedure or #f otherwise.

So I checked of course:

Welcome to DrScheme, version 203.
Language: Pretty Big (includes MrEd and Advanced) custom.
> (primitive? car)
WARNING: Interactions window is out of sync with the definitions window. Click Execute.
#t
> (primitive? map)
#t
> (primitive? list)
#t

help!  I figure this is my error, so I didn't send a bug report.

-- 
Bill 
<http://www.math.nwu.edu/~richter>