Operating system: Win 10 Pro 64 bit
Graphics card: NVidia GTX 780
Blender 2.81 2019-10-09-22
Sun color not adjustable , sun size difficult to adjust,(allways to big). Seems to be the same addon as for 2.79 without any changes to 2.8,
Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).