السلام عليكم In Ramadan I worked: one day with chainsaw another sanding a fence. I saw my mucus having color from emissions (chainsaw) or dust (fence). At times i spitted, at times I swallowed without passing from mouth. Is correct to repeat those 4-5 days to be on the safe side?

Ustadh AbdulAziz al-Haqqan

Don't fall into waswas. Coloring in the mucus can be from other things as well. All in all, you couldn't help it, and it's not like you swallowed intentionally to break your fast. Therefore, don't open the door of waswas upon yourself.