Whether your truck is tan, green, woodland or a collection of different colored parts, unfortunately you will never match the color of faded CARC paint - unless you specifically have a new paint made that is whatever degree of fade you have but then it won't match in a few more years of sun exposure as the different paints likely won't fade at the same rate or same way.
That said, for ease of use and proper color match and just plain availability, I'm a big fan of Rapco CARC substitute paint. It is available in proper 383 green/brown and 686 tan (for black I prefer Krylon's Ultra Flat black "Camouflage" paint as it is cheaper than Rapco and its spray nozzle is superior, IMO). For little projects, additions and
sometimes touch ups I like the spray cans. I purchased the gallon can when I had my M35A2's hard top professionally sandblasted and painted. Be advised that it is not as flat or chalky as CARC, that's because it isn't CARC, but it is a flat enamel paint. Though some complain about it having a slight sheen. I personally think it looks great and I love it.
Buy it by the gallon, case of spray cans, or even individual cans as you please and budget allows:
http://www.rapcoparts.com/manuals.html
I know of a local source (to me) that will sell actual CARC to civilians (see the below link for the info in my thread), but in 2016 it was over $180 per gallon.
https://www.steelsoldiers.com/showt...M66-Gun-Ring&p=1882531&viewfull=1#post1882531