Hey, Cybril, I see where you're coming from and yeah, lots of people do have their own characters that are usually dark, true. If you want a straightforward answer to your question on what you should do, it's this;
Do exactly what you intend to do.
Who's to say your character is not original? Even if it's a generic dog or a bright colored panther, if you made that character on your own, it is original. Make the characters you want! If anything, if people are mostly dark characters, you'll stand out from the crowd. Which is never a bad thing! The more you stand out, the more attention you get! Whether it's positive or negative view to someone else, the thing is, someone notices you.
So, be yourself, please, especially, if you can. Some people are too afraid to be themselves, so they follow the crowd to be safe. Do what you like and create what you like. You can't please everyone with your character, but there is one person you must please at all times, yourself.