Painting my son's room...advice please!

We moved into our home when my son was 3 weeks old. Because of the terrible timing his nursery is still painted a hideous assortment of colors, including some pink and teal. Not only are they ugly, they're definitely girly (the previous owners had a baby girl and a terrible taste in paint...the whole house will eventually be repainted lol). We know exactly how we want to paint his room, and we will wait until it's cool enough to leave the windows open all day with fans going to air it out. If I started in the morning and put him down for his naps in my bedroom, and I left the windows open and fans going all day do you think it would be safe to have him sleep in his room that night? I know I'll have to see how it is that night but what can I expect?