Here's an easy way to color the engravings on your blued steel gun slide. It's cheap and easily removed. The wax from melted crayons will fill in the engravings and add some 'pop' to you gun. If you don't like it, you can heat up the slide and remove the wax with a cloth or paper towel.
I like this method over enamel or nail polish because it's fool-proof.
If you get sloppy, no problem - just heat it up and wipe it clean.
If you want to sell the gun - just heat and wipe.
If you want a new color - heat and wipe and re-apply.
Step 1: Required materials
The materials required are:
Crayon(s) - you can experiment with different colors, I chose white and grey
Stiff paper (I like playing cards)
Notebook or newspaper