🚀 go-pugleaf

I am using direct calls to the IBM 8514/A to paint various graphics
and text to the screen, generally with the desired results. However,
I have been unable to create a desired foreground color: mustard yellow
(The program is running full screen under OS/2.)

I have defined the color as (255, 160, 0) (red, green, blue) which I
believe should produce some sort of yellow. Then I use the HSCOL order to
set the foreground to this color (using the corresponding index that
was determined when I loaded the palette). The background is set to
an index for light grey (200,200,200) using the HSBCOL order and mix 
for both background and foreground  set to overpaint (2) using the
HSMIX order. The text is then written using the HCHST order. And it
comes out pink. I have tried the default yellow from the palette and
adjacent colors in the custom palette with the expected results.

As near as I can tell, blue is getting mixed in somehow.

Any ideas on what I am doing wrong would be greatly appreciated.