The 15500 isn't for everyone, usually the negative comments come from people who have never seen it in real life.
I have seen only the grey and black versions in person, and I think both are great. I own both the gen 15400 and 15500, and I have to agree that both wear very differently, with the 15500 being thicker, less elegant, less refined in feel, and more sporty. Strap one on your wrist and don't depend on google pics to make your assessment. I think it will change your mind like it changed mine. Of course, it is not too late to find it ugly and unsuitable for you then lol.
In the same way, I thought the code 11.59 was ugly when it first got released, and I tried one on physically and my opinion remains unchanged. Opinion sealed. My point is that, yes the watch may eventually turn out to be something you dislike. Yet, almost all timepieces need to be perused in person for the details to be appreciated, and of course, there is the proverbial wrist matching/chemistry.
There is no argument that blue is the best looking dial color though. I'll encourage you to go try one on yourself (whatever color you can get your hands on), it will be a game changer for you specifically I think, with you being on the fence and leaning lol.