To expand the design to see the color breaks in their order of stitching, click on the triangle/arrow next to the picture of the object (see picture).
If you click on a single color in the object pane, it will highlight on the Design page - and if you look at the properties pane on the lower RHS, you will see the color chip for this individual color. Yes, you can change this color by clicking on the color chip.
By clicking on each color, you can "step thru" the design, just like you would at the machine.
To delete a single color in a design, hit the delete key while that color is selected in the Object pane.