On Tue, 29 Aug 2006 17:39:23 +0200, Thierry wrote:

Is there somewhere on the web something that could help me to pick up the
exact color of each spectral class ?

Stars are almost black bodies, so you could use the Planck energy
distribution formula to calculate the energy emitted at visual
wavelengths. You also can look up spectra in reference books. It
might be easier to create a tint based on color temperature
corrections in graphics arts software, each spectral class having a
characteristic surface temperatu

Class Temperature Star color
O 30,000 - 60,000 K Bluish ("blue")
B 10,000 - 30,000 K Bluish-white ("blue-white")
A 7,500 - 10,000 K White with bluish tinge ("white")
F 6,000 - 7,500 K White ("yellow-white")
G 5,000 - 6,000 K Light yellow ("yellow")
K 3,500 - 5,000 K Light orange ("orange")
M 2,000 - 3,500 K Reddish orange ("red")

The tints of real stars are very unsaturated and you would want to
exaggerate the colors to get a good appearance. An ordinary
incandescent lamp filament at 2,900 K is similar in temperature to a
class M star and appears "white" to most eyes.

Bud
--
The night is just the shadow of the Earth.