The reason your silver aircraft may have showed up so hot is because
your "heat gun" was actually peering at the image of the sun reflected
off the glossy surface. But its is true, the apparent color seems to
have little correlation to its IR characteristics. The guy that
suggeted using the back surface of a test panel and measuring the
temperature directly (thermocouple into to DMM or non contact
thermometer) was right on. Also, you could always go two tone on your
airplane with the top surfaces being IR reflective (and preferably
visible light absorbative on the cowl) and the other surfaces any
color you want.

cal (BD5ER) wrote in message ...
The aircraft is a composite Lancair 360.

Looks like you should stick to the light colors, white, yellow, silver etc, and
keep the dark trim colors to a minimum.

I once took one of those infrared heat guns with me to the auto auction (1000+
vehicles) on a wind free day. While there can be some error with the IR units
I did come up with some real surprises - like silvers that get WAY hotter than
you would expect and some rather dark colors that weren't that bad. I suspect
there is more to how hot the paint gets than just the color, like the kind of
flake, pearl, or even the clear coat.

White is boreing, but it's the only fool-proof color I know to paint a
composite plane.