K-rend thincoat over HP12 Basecoat.

Hi all, I have been asked to k-rend a garden wall which has been built with semi-engineering bricks. The wall was built using the wrong sand and cement joints. The client doesn't want an organic finish, and also wants a dark grey colour. My queries are :-

1. Do k-rend do a dark grey mono top coat ?
2. Can silicone thin coat be used on top of the HP12 base ?
3. If question 2 is a yes, can I buy grey plastic beads ? (hopefully 6mm)


Thanks for your time.