Please be mindful this is a vintage model sterling silver from Montblanc. The mechanism is different. You face on the code window/index on top and push it to get the color out. But when you want to tetract it back, you need to turn to the other color face up and push the cap. So when you want the second color out, it’s somehow may feel strange that you need to push twice( first for previous color retract back, second for new color comes out) please check the video in detail. And please be mindful as this is very old you am may need to understand sometimes it may stuck accidentally when the strength of push is too big. There are several dents on it as show in the photos