How to use meld for git and configure meld diff tool colors

sudo apt install meld

emacs ~/.gitconfig
Add:
[diff]
    tool = meld
[merge]

    tool = meld

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Configure meld external editor:
emacs -fh -geometry 180x160 {file}

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For Version: 3.0+
sudo emacs /usr/share/meld/meld.css
For syntax colors:
sudo emacs /usr/share/gtksourceview-3.0/styles/classic.xml

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Change classic.xml magenta definition to