Black and white filter creates dramatic looks instantly — it removes color distraction and adds impact.
Steps to add black and white filter
Select your layer and go to Effect → Color Correction → Black & White.

Adjust the sliders for Reds, Greens, and Blues to control tonal balance and how dark or light each color becomes.

Preview until it looks right for your shot.
One more thing
Instead of Black & White, try Hue/Saturation set to Saturation: -100 or use Tint for faster control and more creative options.
Related how-tos
How to use color grading effects in After Effects
How to create a vignette effect in After Effects
How to add noise and grain in After Effects
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