Professor Paint

Today I stopped by Lowe's to buy paint to match my new siding. I've decided to paint the front door the same color as the new contrast siding. Lowe's (and probably others) have a great computer program that you can put any color swatch up to and it will make paint the same color. It's really cool and being excited to get the paint, I had a swatch in hand. What I wasn't expecting was to get a lecture about how it's too cold to paint! So, am I not allowed to buy paint before it's warm enough to paint outside? Weirdo lady... some people like to plan ahead! Speaking of which, I will need just a little primer so those of you who have some, don't throw away your cans with just a little dab cuz that's just what I need. :)