This was, since I had started painting in 1995, the coolest project I've ever done. This was an exterior T-111 repair and a wood / shed waterproofing and an attempt to make the hardie board appear as if it was aluminum or a metal to tie in with the roof and give it an "Industrial" theme.
All of the cedar wood was protected with BEHR Waterproofing Wood Finish in a transparent base in an off-the-shelf color called Cedar Naturaltone - this includes the cedar header across the top around the outside, the floor and the supporting posts.
All of the lower PT was protected with BEHR Waterproofing Wood Finish in a solid color base tinted to Dark Everglade.
All of the hardie board was primed with BEHR Marquee Exterior Satin in a custom color match (matched to the flake color in the galvanized metal) and then painted to Aluminum with RUST-OLEUM Oil Base protective enamel (off the shelf).
The chimney T-111 was removed and any 2x4 wood that needed replaced was taken care of, then new hardie board and trim was installed and a change of colors from the original - the chimney cap is now painted with BEHR Marquee Exterior Satin tinted to Bear Rug and the hardie board was painted with BEHR Marquee Exterior Satin tinted to Faint Beige.