Can be much better if the color theme of the graffiti letters little bit more brightly or lighter, not too dark. In this picture, the colors look awful. I guess this caused by that gloomy paint. Background for the graffiti letters already dark and the gloomy of letters not helping up the scene, and even worsen the appearance. Bu not all bad to see, the modification letters on this graffiti, is done nicely. And for sure there’s nothing wrong with darken background. Just need for those letters to shine a bit more, the colors having gloomed written all over it.
Trust your pen for paper base material graffiti letters. Like this picture about to tell, for pen is there’s no such thing as hard curve. Flexibility can be earned from this tool. And even there so many choice of tool can be use in the paper base graffiti letters, like water base paint, crayon. But for me, pen is very good choice. In this picture, we can see that only two colors involve, black and red. The white can be made with paper original colors no need to provide one. You can even made that wet looks of spilled paint with this pen. And the result of that coloring is neater if it compare with others tool. So, what are you waiting for? Draw your own graffiti letters!