No. You cannot change the color of the notification light in LG Q6 Plus.
No. LG Q6 Plus is not a water-resistant phone but it is made of incredibly strong 7000 series aluminium.
LG Q6 Plus SAR value is as follows:
SAR Value (Head): 0.72 Wkg@1g
SAR Value (Body): 0.455 Wkg@1g
LG Q6 Plus has 3000 mAh Li-Ion battery which offers talk time of about 16 hours and standby time of about 200 hours.