I had some paint mixed at a local paint store to paint my bedroom walls and ceiling. I have a larger room so i bought two gallons and used them both. When it was all dry, i went back to see how many spots needed retouching and what not and i needed to go buy a new gallon of paint. I had it mixed to the appropriat color and I went home and finished the job. I was ready to store the rest of the paint that was left when i realized that the base paint that was used was exterior paint vs. my interior paint of the same brand i had already been using. I thought it would dry the same color but it's just a few shades lighter and a little more glossy than the regular paint. I don't know if that will faid, or do I need to go and get more interior paint and try to cover all of that up. Please help.

 

It sounds like the sheen levels were different on the exterior and interior paint. Fo instance, the interior may have been flat and the exterior may have been satin. Or semigloss vs. satin. Look at your two paint cans - they will have the sheen level on them.

My suggestion would be to take the old interior paint can (the cloor you are trying to match) to the paint store with you and get enough paint to do the job right. The exterior paint you used will fade somewhat but the interior paint will too.