An option to change app background theme with a custom color

[NeonKokoro]

Describe the feature request

So I'm requesting a feature from uYou but I think the custom color theme could easily work out just like the OLED theme by setting the color value to what you picked via the color picker.

Post requisites

• I have CHECKED that a similar feature request has not been reported before.
• Verified the relevance of the project and the version you are using.
• Provided a detailed description of the request and have filled in all required fields.
• By submitting this request, I confirm that I have filled in all the necessary fields and complied with the guidelines. Failure to comply may result in the request being closed without discussion, and repeated violations may lead to restrict account from further participation.

[NeonKokoro]

WAIT I ACCIDENTALLY CLOSED THE ISSUE @Tonwalter888 I don't have permission to reopen it

[NeonKokoro]

Alright, let's get back to the point

[NeonKokoro]

Also speaking that the last commit was more than a week ago

[Tonwalter888]

#49 I'm still actively maintaining it, just for the next big release.

[NeonKokoro]

oh

Well in that case I'll change KiraTuno's version to either 2.4.0 or 3.0.0