Johny B Good wrote:
The blue LED indicator lamps are the worse for this excessive
brightness issue. On older kit using different lamp colours, they seem
to have decided on the same value of current limiting resistor for all
three colours (red, green and blue) with the result that the blue is
uncomfortably bright compared to the more muted red and green lamps.

I've found that if I pick a resistor value that uses orange instead
of red as the third band on the originally fitted resistor, that seems
to drop the brightness to a more comparable level. :-)

I recently designed a PCB with a series of indicator LEDs for different
power rails, and decided to use a rainbow colour scheme
white/blue/green/yellow/orange/red
All but the white came from the same Kingbright range.

Not only were they painfully bright, they were all different levels of
intensity. I had to spend half a day tweaking the resistor values to match
the intensity across the array. To make it more exciting, the power rails
were different voltages. Some of the resistor values went up by a factor of
100.

Theo