Lineon 100 Pack Gel 1 Count (Pack of 100), 50 Colors Pens with 50 Refills
So we know the key points for coloring: ink and tip. Color specificationLineon 50 Colors Gel Pens contains 50 INDIVIDULE colors. SafeAcid-free and non-toxic, conforms to ASTM D-4236. Lineon gel pens set contains 50 unique colors gel pen plus 50 refills are ideal for adult coloring books.