Toggle Grease Pencil "Use Lights" value using Python I'd like to toggle the checkbox shown in the image with the Python editor in Blender, but can't find anything in the documentation that matches what I'm looking for.
You can use:
bpy.data.grease_pencils['GPencil'].layers['GP_Layer'].use_lights = False

The grease pencil object is:
gp = bpy.data.grease_pencils['GPencil']

Its 'GP_Layer' layer:
gp_layer = gp.layers['GP_Layer']

And its use lights property:
gp_layer.use_lights