What is the difference between the colors ash and gray?

The two Words are not similar in any way. Ash is a type of wood used in bows and some furnitures. Red is a color.

If you are talking about Pokemon then red is more serious, beat team rocket, beat the Pokemon league in one try, and his Pokemon team is different. Ash is more care free, can't beat the Pokemon league in one try, has different team, and goes to different regions. I hope this helped :)