I am replacing the dual filament bulbs in my bullet lights with the cool LED bulb replacements.

The lenses on the signals are already amber in the front, and red in the back.

I can actually purchase LED bulbs that are amber, red or bright white.

Logically, I can just replace the incandescent bulbs with white led bulbs.

However, I've read that the signals will be even brighter if you use the same color bulbs behind the lenses. In other words, use the amber dual intensity LEDs behind the amber lenses, and the red LEDs behind the red lenses.

On the flip side, I've read the opposite as well, that you should never use the same color bulb behind the same color lens.

I have my own theories, but nothing in practice.

Can anyone shed any light (pardon the pun), behind this? Anyone know for sure ?

Sometimes it can act as a filter.

i have a massive red led cluster in my tail light. very bright  the small cheap ones are naff and not as bright as stock