I have stained cedar siding on house. Recently installed new HVAC system with paintable plastic covers on the exterior of house. How do I match the stain on wood to paint on covers?
The best way to match it is to remove a small piece of the siding and take it to any paint store that offers computerized color match. I/E: A piece of window trim, a loose knot hole, or use a painters 5-way tool to chisel out a very small piece from the bottom of a corner board or other inconspicuous place. Also, you might try calling a local paint distributor like Sherwin-Williams. Tell them you are considering some paint upgrades and you would like them to come out and match up the color with a fan-deck so you can weigh your options. If they think there will be a big future paint sale at stake, they will send out one of their road reps to speak with you and match the color. Remember to use a primer on that plastic before you paint it.
I am afraid that would be impossible to match. Stain is absorbed into the wood and not uniform across the entire surface. It is very dependent on the grain of the wood and the red hue in the wood shows up.
You could get an approximate match but the two will always look visibly different.
I agree with Quoc Vu, the match will never be perfect. Acceptable? Perhaps, but that is quite subjective. An alternative approach might be to pick a complimentary color and make it an accent/feature. For example, matching the color of soffit/fascia/gutters instead of the siding.