Lily's trunk | Nancy Drew: Tomb of the Lost Queen

Figure out how to open Lily's trunk:

Read the manual on the floor left of the bed to review how to open the lock.
See colored squares with numbers. This means that there should be that many squares of that color there. The similar colored squares can only be in horizontal or vertical or block arrangement.
Click-hold on a colored square and then move to cover the number of squares you want colored.