Tan wall tyre recommendations?

Panaracer D Evo 3 - amazing tyre (GP4000S2 levels) with brown wall looks.

I'm running it now on Colnago Master and couldn't be happier. It also lasts long.

Whichever you buy, I'd recommend coating the tan wall in silicon or something similar to ensure that they remain wipe-clean....otherwise they won't stay beautiful for long. 

The tires that Kiloran mentioned are the best there are in tan sidewall tires.  Panaracer had a new tire called the Pasela ProTite folding tire with more flat protection than the Pasela plus it folds as does the Pasela PT (some models fold some don't on the PT and ProTite).

Another option is the Clement Strata LGG.  I know that the older Pasela TG was a fantastic tire because I have pair, some people thought the sidewalls were a bit thin but they are no where near as thin has Conti sidewalls so the Pasela holds up really well even with added touring weight.

Another tire is the Vittoria 23 Open Corsa SC II Tire which replaced the Open Corsa SC.

I loved my Vittoria Open Corsas, they weren't very tough though.

Before you go out and buy new tyres, have you checked the rim strip to make sure it wasn't a spoke that punctured the tube and the area around the valve hole to make sure it's not sharp? And you've ruled out a pinch flat?

If there's no cut in the tyre, then it's unlikely to be at fault (punctures from thorns are going to happen, even with puncture protection), so it seems a bit extreme to go and replace them unless they're worn

It's a shame Vittoria stopped making the Corsa SCs, as they were a super nice tyre that didn't cost too much (although more than the Schwalbes). Their replacement, the Corsa G+, is a fair bit more expensive for little apparent benefit

Just looked - you can get Gravelkings in 23c or 26c - you might squeeze the 26s in. The SKs are also available in 26c.

Veloflex Master 25 - very supple, very lightweight, relatively easy to fit compared to other Open Tubulars.

Panaracer Pasela - more of a touring tyre but cheap as chips - probably the best option for your needs. Spa Cycles usually have them.

https://road.cc/content/review/234138-panaracer-pasela-pt-folding-tyre

Possibly the Panaracer Gravelking (its not a gravel tyre, has a file tread) but I'm not sure if that goes down to 25c

Conti GP Classic has dark brown sidewalls with cursive script logos - only available in 25c, might come up bigger depending on rims

Vittoria Corsa Gs

Challenge do a range of "open tubulars" with tanwalls. Only buy if you're a master at fitting tyres.

I've got Veloflex Master 25s and Gravelking SKs, love 'em both. The SKs aren't available in 25s though.