‘Titanium’ strings seem to confuse - certainly confused me in the past. As I understand it they are a form of clear nylon that looks just a little darker than ‘normal’ clear nylon and is very slightly denser and very slightly stronger. I’ve not tried them but intend to at some point, certainly they have supporters here on this forum. SUS have a good video on D’Addario nylon strings, it might help you.
That's right, the Titanium strings contain no actual titanium or any other metal. It's just a brand name. I think the material isn't nylon per se but a very similar monofilament compound. Certainly behaves very much like nylon as it's similarly stretchy. It's slightly purple in colour, and the feel is also similar to nylon but maybe slightly harder, almost glass like as D'Addario themselves describe it. It's actually my favourite string in terms of feel. Sound-wise it's actually probably something that the OP is after. It's brighter than clear nylon but warmer than fluorocarbon. The thickness is identical to nylon, however, so if one doesn't like thick strings then I can't recommend them. Also, in my opinion, they have a very peculiar shimmer/resonance when played and for that reason I think they only suit very particular ukes, usually ones that have some natural warmth to them already. With that in mind, they might not be the best strings for a soprano so I can't recommend them unconditionally. They are quite cheap though so I'd say they're worth a try.
Then again, they sounded surprisingly good on the recent Enya Nova tenor which is a plastic uke, so my perception of them is clearly not universal.