Joanna Stern, writing The New Thing (gift link): I used to love the blinking notification light on my BlackBerry, and later my Droid 2. It was a simple way to know I had a message without actually looking at my messages. Then BlackBerry let you customize the color, and it was a rainbow dream. Google’s HiLight takes it a step further by letting you assign different colors to VIP contacts. So when your phone is face down, you can tell who’s trying to reach you without picking it up. It looks cool...