Yes if it is not white you may have propane fill stations questioning you about it and might refuse to fill.

> Date: Mon, 3 Nov 2014 14:56:01 -0500
> From: ianvincentdow@GMAIL.COM
> Subject: LPG tank ... white paint or varnished steel?
> To: vanagon@GERRY.VANAGON.COM
> 
> I got the tank off my van for the first time. I definitely have to replace
> the valve.
> I snaded and brushed all the rust off, and it looks awesome. My mechanic
> emphatically suggested that I paint it white with rustoleum (brush)
> Same for the protectors plate.
> But I hate to do it. It looks really cool.
> 
> Is there any real bad reason for not leaving it in steel, with several
> coats of varnish or other finish?
> 
> Steam punk, or good sam club?