Do blue marks appearing on a deceased person's body, specifically on the upper back, indicate a bad ending, and what deeds can the reward reach the deceased?

The appearance of certain signs on the deceased is not evidence of a bad end; for example, if one dies by fire, they are a martyr. What is required is to think well of a Muslim and to conceal their apparent faults. As for deeds whose reward reaches the deceased, some are agreed upon by scholars, while others are disputed. Some scholars are of the view that the deceased receives the reward of every righteous deed whose reward is intended for them, such as supplication (Du'a), seeking forgiveness (Istighfar), prayer (Salah), fasting (Sawm), pilgrimage (Hajj), and recitation (Qira'ah).