I'm installing 16x16 steps (2 aside) along the back of my house. I
have chosen the red color that are embossed (looks like 8 bricks in
there).

They look to need some cleaning as there is some white substance, then
I want them to look like the photos in the flyer, they look almost wet,
perhaps sealed like my new curbing in the front.

any ideas how to clean these up and do I need to seal them?

Thanks