Are there any Manufacturers of Blue Diodes ???
If you are looking for blue LEDs, you might want to try the LED museum.
I meant the Diode made of Gallium Nitride (GaN) which can produce light at ~ 400 nm ...
Discrete Gallium Nitride blue spectrum LEDs
400nm is violet, according to the following links table at the LED Museum:
515-540nm True Green
485nm Sky Blue SiC
445-480nm True Blue
430-440nm Deep Blue
Separate names with a comma.