Scribbling, with a back and forth motion is the scoring criteria.
The colour may be applied anywhere on the paper. They may not be looking at the effects of their actions nor paying attention to the lines on the picture.
The addition within ACL 3.2 is an intentional back and forth motion, using an object held in their hand and causing an effect on another object. Within ACL 3.0, an object is held, but there is no conscious cause and effect connection with another surface. As a concrete example, the person holds a crayon within ACL 3.0 and applies it to paper within ACL 3.2. The motion on paper looks like a scribble until you look closer and see that the back and forth motion is the beginning of tracing over a line.