Could it be the 3.3 resistor?

 

Can anyone figure out why the "u" is a different shade? Could it be the resistor or the actual leds?

Peter

 

Looks like the "U" could be cool white vs. a warmer white on the others.

Hard to tell tho.

 

Can anyone figure out why the "u" is a different shade? Could it be the resistor or the actual leds?

Peter

Seriously doubt it's the resistor. Slight color variations between LEDs are pretty common, and some LEDs change color a little bit with age.

Sometimes we perceive color a little differently depending on brightness, so it's conceivable that you could alter the relative brightness of each letter by using different resistors on each, and you *might* see a difference in perceived color, but I don't really think that's what's going on here.