Critiquing yourself is something that all photographers have to do. It's also one of the harder things any artist has to do because often the image in your head doesn't match the reality. Part of this process happens when you dkwoad all your photos and start sorting through them. If you shoot Raw, all the photos are in colour, regardless of the camera settings, so at the time you release the shutter you don't have to worry about the colour.
When it then comes to the post-shoot edit, one of the seemingly 'easy' tasks is to decide if the photo looks better in colour or black and white. I used to hide bad focussing or colour tone by using B&W (shhh... sometimes I still do!), but I've come to terms with the fact that occasionally, black and white just looks better. But you can spend an age flicking between colour and mono and never come to a conclusion.
Certainly with a wedding shoot, there's a general rule that "emotional moments always look better in B&W". The reason is that there is no colour to distract you and makes the subject the clear focus of the image. But with something like a commercial or product shoot, colour is important to faithfully recreate the subject. You will rarely see a black and white food photo.
One thing many of my photographer friends do is post both the colour and B&W shots on Instagram, inviting 'likes' for esch. I suppose there's no harm putting it to a public vote and I've thought about doing it myself. My worry is that it becomes about what the 'viewer' likes more than my vision and what I wanted though.
This subject is massive, so as a last point, portraits can look amazing in both colour and B&W. Deciding which is another subjective decision, but for me, B&W becomes all about the light and shadow, less about the balance of colour. It brings out subtle skin textures and can elevate any portrait.
Do you have a preference? Let me know in the comments! I'll leave you with this colour photo that looks B&W ;)