Background Color

Hi all,
I just wanted to change and add some of the available background colors for columns as mentioned in your documentation here: https://github.com/liip/bootstrap-blocks-wordpress-plugin#wpbootstrapblockscolumnbgcolors
But honestly, I don’t know where to add this JS snippet, to make that change actually work and being visible in the Gutenberg Editor.

Thanks for your appreciated help, Pascal

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