Hot air and hot sun also affect the ability of those rich colors to develop. I wanted Chianti SO badly all those years ago because of that color...and it NEVER produced anything richer than cerise in my conditions. Plus, being once flowering, it would set buds, the heat would arrive as if someone had flipped a switch and EVERY ONE of them exploded into fried cerise used Kleenex globs. I sent it to someone who really wanted it. Notice where the photos of the roses you really admire the coloring of are taken. Too often, they are the opposite of your conditions.

This one has dropped out of the catalogs here, though it used to be one of the most recommended, I guess for its historical importance if not for its vigor. The first thing I would say is that rose bushes often take several years, or more, to show their nature. They have to build up a strong root system. The second thing is to ascertain is if you are sure that you have the true variety, since mistakes happen, A, and B: this one has been noted as confused in the trade.

Climate of Tuscan Apennines not notably harsh, though, I would imagine. Maybe I'm wrong.

"fried cerise used Kleenex globs" LOLOLOLOLOL!!!!

I found this interesting link which might help with ID:

http://www.lesrosesduchemin.com/2018/10/souvenir-d-alphonse-lavallee.html

Years ago I saw Chianti a t Rose Barni, which is not far from here. It was beautiful! but that was almost 20 years ago, and the climate here has changed for the worse; all too often we get terrible heat waves WAY too early in the season. For this reason I avoid once-bloomers unless I know that they start early in the season,and have no interest in the late bloomers that "prolong the rose season". Rosengarten Zweibrucken ,for this reason, has been a huge disappointment,because it blooms so late in the season. It even keeps its' colour in the heat,but I can't appreciate it much when being outdoors is just such a misery. However, in the case of my Souv. d'Alphonse, I don't know that heat has much to do with it, since it's in a pot at our house,and only gets morning sun. Hopefully it will improve with age.

Monarda, thank you for this link; very good to see the different flowers compared.Our climate here is harsh in the summer, but not so much as that of southern California-at least not yet, and keeping my fingers crossed...

Just to add, Souvenir d'Alphonse Lavallée is supposed to have formal, precise rather cup-shaped blooms, whereas the multiflora hybrid Erinnerung an Brod, which is often substituted for it, though beautiful, has rather muddled blooms.
Growers recommend that both hybrid perpetuals Lavallée and Souvenir de Docteur Jamain be grown in some shade to preserve the color of their blooms. The old catalog, Roses of Yesterday and Today, which I used to eagerly devour at my mother's house in Pennsylvania as a teenager, carried both, and also the exotic, white-edged crimson Baron Giraud de l'Ain. Which you also don't see mentioned much anymore. I guess these old HPs are too big -- or something-- for modern suburban properties. (Just riffing here.)
https://twitter.com/thegardenvsw/status/1023502728541155329?s=20

O, MetteBee. lucky, lucky you-"a cool June day"! By now, June is often almost or just as hot and miserable as July or August. However I do have Erinnerung an Brod, and it does keep it's colour well, even without a lot of shade. I used to have Souv. du Dr J and its flowers were beautiful, but it was not planted properly and wasted away. That rose for sure needs part shade I think, since even the Peter Beales nursery, in grey, cloudy England, says it needs part shade (or did say; on their new site they say full sun ,part shade or shade). For Souv d'Alphonse they say full sun. I like to check their recommendations on shade tolerance of any given variety because if a rose tolerates shade in England it will definitely appeciate some here in Italy.