Panic's Developer ColorPicker (v1.5.4) does not work in macOS Catalina or macOS BigSur. This is due to enforcement of code-signing. Until Panic releases a newer version that supports Catalina/BigSur, below is the workaround.
You need a Developer Account. This could be a free account. Refer: https://9to5mac.com/2016/03/27/how-to-create-free-apple-developer-account-sideload-apps/
https://panic.com/blog/developer-color-picker-1-5/
Unzip and copy DeveloperColorPicker.colorPicker
to ~/Library/ColorPickers
Code sign
security find-identity -p codesigning
Verify whether the above command lists at least one valid identity. Among the identities copy the identity name with which you would like to sign. Identity name will be a text in the format "Mac Developer: [YOUR_EMAIL] ([YOUR TEAM])"
cd ~/Library/ColorPickers
codesign --force --sign "Mac Developer: [YOUR_EMAIL] ([YOUR TEAM])" ./DeveloperColorPicker.colorPicker
If you do get the error ./DeveloperColorPicker.colorPicker: resource fork, Finder information, or similar detritus not allowed
,
execute the below command and re-try code signing.
xattr -cr ./DeveloperColorPicker.colorPicker
Hello @Mick536
As you rightly mentioned, the Youtube video you mentioned is to create a self-signed certificate. But am afraid a self-signed certificate wouldn't work.
Instead, we need an Apple-issued developer certificate. You could get it for free. You may use the content link in the prerequisite section as a guide to creating one. You would need to download Xcode which is again a free developer tool to have the Apple-issued developer certificate on your Mac. I am unaware of any method that doesn't require an Xcode installation :(
Happy Thanksgiving to you too :)