[HWYSTR455]

Can always do pin stripes, those never go out of style, and depending on how their' done, are classy too. If you want to get a little creative, you can do a Pontiac arrowhead somewhere too, like at the end of a body-length pin stripe. (Chevy heartbeat can be an example)

Maybe consider someone who can render some ideas for you, can sit there in front of a terminal for a few mins and actually see how different accents look. For the nominal cost, it can be totally worth it. Print a couple you like out, take them home, and can think about it.

Some factory-type combos with dark grey/charcoal use stripe colors that are red, white, silver, and black (on lighter base colors). You can even do 2 colors, one stripe red, one white, or something like that.

Can even do graphics on a 2-tone where lettering is broken, or faint using fine stripes. (Think late '70s Formula graphics above the rockers as an example)

I googled 'Pinstripe colors for charcoal cars' and came up with a bunch of pics as examples. Maybe other search strings that are similar can give you some ideas.

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