Incomplete B&W Conversion in Lightroom Classic

[Michel Bérubé]

I recently converted a colour image to b&w in Lightroom and for some reason parts of the image preserved some of its colour. Transfering the same image to Photoshop and changing the mode to greyscale corrects the problem. I have never experienced this issue in Lightroom before. Any recommendations?

[dj_paige]

How did you do this conversion to B&W? Please give us step-by-step details.

[richardplondon]

One thing to check is that colour grading / split toning, and also Tone Curve when set to varied RGB info, can introduce non-grey hues even when an image is fully B&W - or, has been otherwise adjusted to fully appear so.

[Rikk Flohr: Photography]

Tint after BW Conversion can come from two places:

1. Local adjustment with a Tint swatch applied

or

2. Color Grading/Split Toning. 

Those would be places to look. 

[TheDigitalDog]

If you move Vibrance and or Saturation to -100, what do you see (and does the info numbers in the Histogram show that R=G=B)?

[Michel Bérubé]

As it turns out, I had some selective masking applied from a previous edit. This became obvious after inspecting the history. I performed a reset on the image and applied the b&w treatment again with the desired results. Thank you all for your responses.