Colour to greyscale

I’m trying to create a clip where character parts change from greyscale to colour and vice versa as passing back and forth through a door. Am playing with cutter, greyscale and colour override modules but just can’t figure it out. I’m new to this so would appreciate some direction. Thanks

why you cant with greyscale modules?

i probably make the same thing that you are telling, whats wrong?

Would appreciate helpful suggestions please

Just solved it myself with cutter and greyscale. Simple solution!!