Playing with LECOs is more fun that it has any right to be. Here's a colorfulness slider from monochrome to overly colorful.

LECOs are manipulated by their weight and normally need no triggers to use it, change their weight like this <lora:Colorfulness_000000250:-1> to make the color closer to monochrome or <lora:Colorfulness_000000250:1> to make it more colorful, setting it to zero having very little effect on the prompts. Remember you can go further than -1 or 1!