Note: May not work well with other embeddings, although feel free to see if increasing the weight of the embedding using (brackets:) helps in that case.
This embedding will allow you to force an image to be colored, black and white, or both. It can be called with just "b_w".
When using it in your positive prompt, think of it as pouring a big bottle of black and white onto your painting.
When using it as your negative prompt, think of that exact scene but in reverse.
It does sometimes refuse to work, but I find it a pretty handy tool so I decided to share it. ^.^