So first things first buy good painters tape, then tape out your stripes using a level on each strip. You will usually find that no matter how hard you try the ceilings and the floors are not totally level so I try to put the design above and below far enough that it's not obvious if it's a little off.
Next use some of your base colour in my case Stonington Gray ( HC-170)
and paint over the edges of the tape to seal them. That way if anything bleeds underneath it will be your base colour not your new stripe colours.
Then I painted my stripes using Startling Orange ( 2016-10), and Old Pickup Blue (2054-60). To make life easier I left the original gray between each stripe so I didn't have to paint fresh paint over fresh paint. I used Aura by Benjamin Moore which is two coats maximum any colour and dries in an hour so my work was easy and quick. The longest part was the taping but well worth taking your time to level. Within a few hours the room looked totally different and my son loved it which is what I was looking for! So next time you think about it, just try it and you will be surprised how easy it can be...........