As to B&W, I see the world in colors 
You may be partly joking or not, but some very serious photographers think exactly the same way, and when you consider their pictures, you can understand why they believe as they do - quite apart from the obvious fact that we all see in colour - unless colour blind. It's a choice: sometimes it's based on subject but possibly also quite as firmly on psychology and feelings at the time. All external factors can 'colour' your emotional state. Photography is subjective, after all, and how the person feels is how they are at that moment.
Mostly, these days, I like messing around with b/w and that's what I tend to seek out on my wanderings. Yet, sometimes, regardless of what you think you are on the watch for, the opposite comes along as a present. It's up to you to accept or to reject.
Looking for gloom, I found this, a couple of days ago:

Life is a gift, as are your opportunities; you mustn't deny them, ever.
Rob C