Generally, you get the most bang for your bucks when you remodel the kitchen and the bathrooms.
Paint colors are personal choices so if you plan to sell, I would reccommend you stay with neutral colors - eggshell, off-white, etc. Yes, boring colors but they are bright and highly saleable colors. Definitely NO dark colors.
Current trends - vinyl is out hard wood flooing is in. Put yourselves into the buyers shoes...if you get to start all over again with your home, what would you do differently?
You don't have to spend top dollars for top of the line materials. Look around your neighbors and spend as much as they are spending to remodel their homes. Go to open houses in your local neighborhoods to find out. Be caution of overspending more than the average value of the home in the area. You just need to spend enough to make the home looks and feel new and neutral.
The key here is the "overall visual" flow and feel of your home. Mismatch flooring and/or colors will turn off the buyers.