add the option to choose the secondary color in custom theme

[Turhvjbufv]

Describe your suggested feature

In #160(#269) support for choosing main color was added, but secondary color didn't get added in the end, wish for that to happen please

Other details

No response

Acknowledgements

• [X] I have searched the existing issues and this is a new ticket, NOT a duplicate or related to another open or closed issue.
• [X] I have written a short but informative title.
• [X] If this is an issue with an official extension, I should be opening an issue in the extensions repository.
• [X] I have updated the app to version 1.11.2.
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