Color Replacement tool not working properly in Photoshop 2020

[UnderDogNowOnTop]

I've been trying to mesh the color of the lemon to her skin for hours now, At first it wouldnt allow me to use the color replacement tool. Then I changed as you can see below 

at first it would not let me came up with error everytime 
could not use color replacement tool because it only works in full color modes photoshop 2020
then I changed the setting I changed from Cmyk to SRGB

What is the best setting I should be using, is there some sort of bug going on? I was watching a Fruit Blend with Will smith from a guy in England, the video was from 2012 and it worked for him.Then I found another old video telling me to change the settings, video was so old it gave out a 1800 number at the end if people needed help. I have a Entry level gfx card. Shouldnt be a problem.

Would really love to know as I found out there's money in Drum/Sound Kit graphics on instagram.

[c.pfaffenbichler]

What does the Proof Condition have to do with this? 

My recommendation: Don’t use the destructive Color Replacement Tool at all. 

Use Adjustment Layers instead. 

[UnderDogNowOnTop]

Ill tinker with it, but that doesn't mesh with it. I have to do more research, thank you for answering.