To the OP, you say you shoot Raw, have you ever tested this out for yourself? Take your camera and set it to shoot monochrome/B&W, take a shot(s), what do you get?
If you look at the LCD preview, you will see the B&W image. This is because the camera creates and stores a jpeg in the Raw file, using the in-camera settings, so that it and the histogram can be viewed and evaluated.
Then download and open the Raw file in your Raw processor. What do you see?
If you use the Canon Raw processor DPP, you will see virtually the same B&W rendering that you saw in the camera LCD, as a "starting point" in your Raw processing (all those settings can be changed with Raw in DPP).
If you use another Raw processor then you will not see a B&W/monochrome image, except for the very start of when the image first shows up in your software. In that case your software may show the embedded jpeg while it is rendering the Raw data into an RGB image. Then, quickly, the Raw/RGB rendering should show, and lo, it will be the "standard" rendering that your software applies to all your Raw images, full color but ready and waiting for your creative efforts!
Please try it out and get back to us with your results and if you have any questions...otherwise we are wasting bandwidth by repeating the same stuff over and over again!