Driving LED's with PWM

[Demon]

If it's a panel inside then you could supply 1-3mA per LED. There's no reason to supply the maximum amount of current since you won't have an audience to view them and they are inside. ...

I'll be using surface-mount LEDs that I have on hand (got some greens, yellows and reds). I think they require somewhere between 15-20mA to be reasonably visible in daylight inside the house (some panels could be in full sunlight).

I'll be making my own light chimneys with clear liquid plastic from Smooth-On.

Finished preliminary testing today, very low current is achievable, I just have to improve code logic and efficiency:
http://www.picbasic.co.uk/forum/showthread.php?t=18906

Of course none of the colours I have are of the same brightness so some tweaking of the resistors will be necessary.

Robert