On May 28, 2007, at 4:37 PM, Ingo Klöcker wrote:

Alpha is pretty much irrelevant for the normal user of colors. Moreover, 
alpha is something a bit artifical since it doesn't occur in the real 
world. At least not in the same way as in computer graphics. OTOH, 
mixing colors is something that everybody should know from his or her 
childhood. Alpha is important for people doing computer graphics, but 
for most non-graphics application developer colors are opaque.

Would you think alpha has any use in a music application ? Yet in Rosegarden we'd be very glad to have it, because it would spare us the extensive computation of specific color values for when music segments overlap each other. Also, having been an OS/X user for a bit more than 6 months now, I can vouch that translucency has many good uses, (as in "actually useful", not just flashy).


I will 
rarely if ever change the alpha channel of a color and in fact I mostly 
want to ignore that the alpha channel does exist. I don't want to have 
to think about it.

Then don't, in a sane implementation the default alpha value should be set to 'opaque'.


That's my view as an application developer whose 
most important need for color is the colors showing the validity of 
signed messages.


Many others might have different views, and not just computer graphics people. 


--
Guillaume 
http://telegraph-road.org