Panel button color in v8 not comaptible with v9

I am a recent transferee from IP V8 to V9 and am learning my way.  I have a number of Panels containing buttons and hoped to use them without modification. 

Button buttShowTSR,pos={300,155},size={75,25},proc=buttShowTSR,title="ShowTSR",fColor=(0,600,100)

However, in v9 the  fcolor parameter for button operation generates a black rectangle instead of the V8 coloured ones.

This is probably as a result of the improvements to Panel in V9 but what do I need to change to specify button colour?

OK a bit of experimentation and the full color value works

fColor=(65535,65535,0)
fColor=(65535,0,65535)
fColor=(0,65535,65535)
or
fColor=(0,0,65535)

but

fColor=(0,0,6553)

gives a black button

I see; Igor 8 just used the hue but Igor 9 is using the brightness, too.

I'll take a look Monday.