would it chip?
If you are spraying the same kind paint that was already used another the solvent in the new paint should soften the underlying paint and bond to it though when changing color sometimes some the pigment in the underlying color can dissolve and mix with the top coat. Certain paints are incompatible with each other. Latex paint usually won't stick to oil or alkyd paints unless a primer or deglazer is used first.
If the paint has a sheen to it, like high gloss or semi gloss, it's best to give it a light sanding before spraying on more paint. That will make it hold.
I don't think it would. It's just painting over paint.