Many to choose from. I tend not to like the overly bright brash and gaudy colourings of many. The
Ribble Sportive for instance, too much imho. Not picking on
Ribble btw, just using them as an example.
I like understated paint work, simple lines with an almost retro or classic reference point. I'll google around to find a picture of what I mean from the current offerings.
A clubmate and his wife where on their Follis tandem yesterday. (Follis is a now defunct French make, btw) It dated from maybe the 60s and was a thing of beauty. An almost Ducati-like trellis frame (a reference only of use to motorcycle folk sadly)