It's always best to design an enclosure around a specific animal's needs rather than design an enclosure and try to figure out what animals might like living in it later.
Personally I wouldn't house a newt or salamander in that set up. It looks like there's heaps of gravel and soil sitting in water, which over time will become stagnant and rank, eventually affecting the health of the inhabitants. For a water area that small you may as well just sink a water dish or tub into the substrate.The cork tile background is not aesthetically pleasing to my eye (unless your pet needed a notice board perhaps...) and I'd be worried a newt might crawl behind it and get stuck. It's also a great ladder for any animal with aspirations of escape.
Apologies for sounding so negative, especially as you appear to have put quite a bit of work into it. An aquatic enclosure with deep gravel is generally a bad idea unless you can find some clever way to continually flush water through the gravel bank.