I kinda saw that some others were using a size of 200x200 for their Light object texture, so I did the same when I made my own.
One example of this in use is creating a cone light image to have cone lighting. As can be seen from this GDevelop example: Lights - a game example from the GDevelop game making app | GDevelop
Another is using the Render section of GIMP to kind of try creative lighting for a level with the texture.
I’ve only tried textures that are black-and-white (with shades of gray) so far.