iOS app is rejected as "Spam"
The guidance is really quite straightforward. You need to do what is listed under "Next steps" and/or communicate with the Apple review team to solve the issue, primarily


  When creating multiple apps where content is the only varying element, you should offer a single app to deliver differing content to customers


Basically you're in violation of the guidelines as having multiple identical apps with only color theme variations is not allowed. You could instead create a single app where the user can select the color theme they wish if you agree with the characterization of multiple similar apps. 

If you don’t agree then a chat with Dev support or a formal appeal would be your next step.