Brightest tiny led 3.3V/5V

Bjack795:
Hi all!

I'm looking for a led to use as a "lamp" in the darkness for an Epaper screen.
I'm using a wemos D32 pro board working at 3.3V (I have the possibility to have a 5V output too).

The led must be placed in a 1x6x1.5 cm box so it should be quite small.

I'm looking for the brightest possibility taking into account these constraints.
(Of course there is always the possibility to use an external power source but this is not what I'm looking for)

Thank you in advance

Would help if you told us where you have looked.

Paul