Hi Bertrand,

Aha! I should have realized it wouldn't be anything quite that easy...

(For those wondering what Bertrand is talking about: see

http://www.projectpluto.com/update8b.htm#horizon

The horizon file provided there includes a blue tint near the horizon,
plus some new objects.)

You're right; changing the color of these objects is not so easy.
The only way to do it would be to edit 'objects.dat', then change the
colors given for the triangles that make up the horizon. For each
triangle, three colors are given (one for each corner of the triangle);
in between, the colors are interpolated. For example, consider the
first few lines of the revised 'objects.dat':

; A description of this file appears at its end.
; A 'segment' of the blue horizon tilt, covering a ten-degree segment: */
o blue_segment
r -5 0 7.5 8
t 3 7
-5 0 7f0000
-2.5 3 3f0000
-2.5 0 7f0000

'7f0000' and '3f0000' are RGB color values. The first corresponds to a
half-intensity blue; the second, to a quarter-intensity blue.

You could adjust these to be fainter colors, or shades of red, or
something else.

I didn't work very hard on making the horizon band adjustable, because
I felt that the 'realistic sky' option made it almost obsolete.

-- Bill