Goddess Kali is depicted as very violent and dark you could say, representing the wrath of the Gods against evil.
I guess a better response from me would be not to repress that aspect, but to know when it appropriate to use. 99% of the time it's better to be positive/light, dark/violence should only be used to fight back against attacks.
Also there's nothing wrong with a dark aesthetic, however this should be differentiated from a dark attitude(so wallowing in negativity, like fear, hate, anger, violent thoughts/emotions) which pollutes the aura. These feelings exist for specific scenarios and shouldn't be expressed inappropriately unless you've repressed them before and want to release them to get the energies working properly.
That being said, the Gods are mostly, if not entirely based on the light, even the "dark" ones( which energies were turned dark due to enemy curses) were mentioned by HPS Pythia as wanting to return to the light. Lilith told HPS Pythia that "Light is power".
Darkness is also light turned inside out according to Baal Zebul so I guess the two polarities could be interpreted as two sides of the same coin.