When I was sleeping, I dreamed that I was walking on the road and saw many snakes of different colors.

Snakes in dreams generally appear as Teng snakes. Teng snake is a local snake, usually a small land somewhere. The yellow one should be the city god. Maybe you accidentally stepped on something, or bumped into something underground, or nailed something to stop them. Let them remind you, find it and correct it. Or go to the city god temple and the land temple to burn incense. It's no big deal.