What you will need is some colored Sharpies, rubbing alcohol and maybe a little bit of scotch tape.
If you have some Scotch tape put it around the edges because although the Sharpie won’t stick to the glass it will stick to the chrome edges.
You definitely want to pick colors that you will stay happy with because once the color has seeped into the crack there is no way to go back. Also, when picking your colors you need to keep the color scheme in mind because once you start coloring the colors will seep into the ones next to them.
Once you have your colors you can start coloring. Don’t worry about getting any on the glass that is what the rubbing alcohol is for. After you are finished coloring rub the rubbing alcohol on the glass with a cotton ball.
You just made your crappy phone not so crappy.