Select the box 0001 from the list to the right of the Available Solutions window.
Right click on the box drawing and use the Color option from the pull-down menu.
Choose the color and click on OK.
Now we are going to calculate this box with the new color on File > Recalculate. The new pallets are listed at the end. Click on the box drawing to refresh. You will notice that the box drawing color not always matches the box color on the pallet drawing, this is because QPM keeps the pallets that were calculated with that box before the color change; if you delete those previous pallet, the color will always match.