For the last number of years when testing different powder loads or bullet seating depths, I have sometimes used various colored marking pens such as sharpies to color-code the tip/circumference of each bullet by powder load and/or seating depth. The bullet tips for each load/seating depth have their own designated color. The bullet hole rims on the target paper generally retain the color of the bullet that made the hole. This way for each bullet hole on the target paper I can see (without using a target video) which load/seating depth made each bullet hole by identifying the color left on the bullet hole rim. However, sometimes it is difficult to see the color on the target bullet hole rim. Any recommendations on how to color (which color pens or color solutions, methods etc) to use so I can see the colors on the target bullet hole rims more clearly and consistently so I can more readily identify which load/seating depth created each bullet hole? All comments are welcome!