I imported an imaged to use it as reference to draw it in 3D.
Let’s suppose I want to choose certan color, for example the brown one from the the door of a house.
When I use paint bucket with alt modifier and I click on the image it turns the whole image into a material.
At the bottom left of your color picker window is a rectangle with the current color and next to that is a eyedropper button to sample colors from anywhere on your screen including in the model or outside of the sketchup window.
You have your system listed in your profile, that’s the right place for it. The profile is there so we don’t have to keep posting our systems over and over. Glad you found the button in any case!