I don't kwnow if this can be useful for you, I have a grid with a column (Code),
I change dinamically colors if code > 0 then Red, if code >10 then blue, else black

My code is similar to this:

define class myGrid as Grid
colorType = RGB(0,0,0)

PROCEDURE colorType_ACCESS && Access method
IF CliTel > 10
this.pepe = RGB(0,255,0)
else
if CliTel < 0
this.pepe = RGB(255,0,128)
else
this.pepe = RGB(255,0,255)
endif
endif

RETURN this.pepe
ENDPROC


PROCEDURE Init
THIS.Column1.DynamicForeColor="IIF( 12 > 10 ,eval('this.colorType'),THIS.Column1.ForeColor)"