As I read in the comments that the color was attenuated in time, I put the colorless nail polish (base) above! :)
I see where I have not put the actual color fades gradually. So I quickly dipped my pen in my mini varnish pot!
In addition, I was able to make people happy in my family with these cute pens clinging to perfection on an iPhone, Nexus 4 and Samsung S4 mini! :)
Besides price side, it would be a shame to deprive it of a nice little gadget that quickly becomes very useful! :)