Here is a closeup of the blocking mats:
An advantage of the blocking mats is the color
. Being a light grey, I don't worry about any color transfer to my knitting.
I have heard of the little foam kneeling pads for doing yardwork, and also for gym 'workouts' like sit-ups, etc.
However, I don't know how thick they are, or the color.
I hope these photos help you with your questions.