What is the current trending interior paint colors?

Paint colors are strictly personal taste.

Gray is popular right now and no, all your rooms don't have to be the same color unless you're trying to sell. If you are, then I would stick with the same neutral palette throughout the home .

But if you want each room to be different, you can't do better than going to Lowes or Home Depot and using their computerized paint sampler. You can tap on the screen color and the little house sample changes to your taste. It's epic!!

I've thought about gray. I'm not selling so I may add a different color for the bedrooms. Any other suggestions?

Revere Pewter by Benjamin Moore is an awesome neutral color and so is Simply White by Benjamin Moore. White Dove is another Benjamin Moore awesome color. If you are going for big impact (say in a bathroom or bedroom), would you believe Black (Totally Black by Behr) is rocking it right now and matched up with Simply White BM is gorgeous!