Thanks for writing your query.
Some people are allergic to smell of paints. There might be a possibility that your child is allergic to the smell of paint and have developed symptoms which resemble to that of cold
You should remove the contact of the baby to the smell by shifting the baby to another cleaner portion of the house.
If the symptoms persists, get your baby examined clinically.
Antihistamine drops can be given after discussing with as the Paediatrician.
I hope this is helpful to you.