It's valid syntax for COLOR clause meaning that 2nd color in the color set is changed. If you remove comma than it'll be 1st color which is not the same.
Why do you think the comma causes a problem?

>

>DO 3DBOX WITH 7.212,6.750,2.934,114.150,-1.8,255,255,255,96,96,96
>@ 7.429,7.250 EDIT m.descr ;
>	SIZE 2.500,81.000,0.000 ;
>	DEFAULT " " ;
>	FONT "Courier New", 8 ;
>	SCROLL ;
>	WHEN ddWhen("pdrf.Descr") ;
>	VALID ddValid("pdrf.Descr") ;
>	MESSAGE ddMessage("pdrf.Descr") ;
>	ERROR ddError("pdrf.Descr") ;
>	DISABLE ;
>	COLOR ,RGB(,,,255,255,255)
>

>The comma following the COLOR is the cause of an error. Has anyone seen this happen?
>
>The SPR is created from FoxExpress, GenScrn, GenScrnx, Tabs, FoxScrn, or Combination.
>
>How can I generate an SPR and not have this comma following the COLOR designation?