The community member is trying to set a black color to 60% opacity, as explained in a video by @John Siciliano. The comments suggest two ways to achieve this: 1) Drag the bottom slider to the left to add opacity, and 2) Manually edit the last number in the color field to .6 to set it to 60% opacity. Additionally, a community member mentions that in the future, the ability to work with other color types like RGBA directly in the color picker will be added.
Drag that bottom slider to the left and itll add opacity. If you want to get it exactly at 60 then you can manully edit the last number in the field to .6