It seems to me that the blue light is very weak, can it be amplified somehow?

Hi, I'm not the creator but I've searched about increasing the luminosity and range, so go onto the zip, open prototypes and open entity.lua
Then replace the line 94 :
light = {intensity = 500, size = 40, color = {b=.1, a=.1}},
by
light = {intensity = 5000, size = 40, color = {b=.1, a=.1}},
(change 500 by a higher number)
You can
You can also change size to increase the light range.
You can do the same for other lights as you want!

Hi miroslavpocta & gaulerie,

I will have a look at this mod and maybe add controls to adjust the brightness and range of these light from within the settings.

Will keep you posted!