Our natural vision is in colour. My "normal" way of imagining a composition is when colour is an integral part of it. Actually this is already a statement that suggests an overthinking which isn't there. Colour is your normal environment. Colour photography is a description of your environment. It's less "compositionally involved" than B&W so to speak.
A subject works better in B&W rather than in colour when you want to stress shape, contrast, geometrical relations between the elements of the compositions, perspective, whatever. A subject works in B&W when it has a "graphic" quality.
With B&W you stress those elements of the composition (shape, geometries, lines, shadows, contrast), and your composition works just because you stress those elements. By taking away colour, the rest of whatever makes an image is more "stressed" than it would be with colour.
So B&W is, in a sense, more "abstract" than colour because with colour you take a portrait of a certain portion of reality as it is, while with B&W you use what you see in front of you to make a composition where geometry, shape, lines, contrast, shadows etc. create the picture "regardless" so to exaggerately speak of the real subject of your pictures.
So my advise is: think less "photographically". Look around you. Get an interest in "things". When shooting colour, composition is merely a way to better describe the "thing". Your subject is the subject, not the various games played by geometries, lines, shades, "pendants" etc.
The railing of a gate could make an interesting subject for B&W (for pattern, repetition, perspective, contrast, games of light) and a boring subject in colour because colour stresses more "the railing" rather than the patterns and the viewer sees a boring railing rather than a "composition".
So in order to take good colour pictures you have to dismiss your "professional deformation" and stop thinking in terms of patterns, repetitions, perspective, contrast, correlations, pendants, shadows and just assume an attitude of mere "description" of the object you want to portray, for which you have to have and portray an interest which goes beyond the abovementioned composition elements.
My 0.02 Euro
PS I only use colour. My "avatar" is in B&W because it's a case where B&W works better than colour.