iOS app is rejected as "Spam" I have similar apps with different design &amp; color theme as per my different client. But Apple is now rejected my latest app as spam
Apple message:

Guideline 4.3 - Design - Spam
We noticed that your app provides the same feature set as other apps
you've submitted to the App Store; it simply varies in content or
language, which is considered a form of spam.
Next Steps
When creating multiple apps where content is the only varying element,
you should offer a single app to deliver differing content to
customers. Alternatively, you may consider creating a web app, which
looks and behaves similar to a native app when the customer adds it to
their Home screen. Refer to the Configuring Web Applications section
of the Safari Web Content Guide for more information.
You will experience a delayed review process if you deliberately
disregard the App Store Review Guidelines, ignore previous rejection
feedback in future app submissions, or use your app to mislead or
deceive users.
Important Information
As a result of violating this guideline, your app’s review has been
delayed. Future submissions of this app, and other apps associated
with your Apple Developer account, will also experience a delayed
review. Deliberate disregard of the App Store Review Guidelines and
attempts to deceive users or undermine the review process are
unacceptable and is a direct violation Section 3.2(f) of the Apple
Developer Program License Agreement. Continuing to violate the Terms &amp;
Conditions of the Apple Developer Program will result in the
termination of your account, as well as any related or linked
accounts, and the removal of all your associated apps from the App
Store.
We want to provide a safe experience for users to get apps and a fair
environment for all developers to be successful. If you believe we
have misunderstood or misinterpreted the intent of your app, you may
submit an appeal for consideration or provide additional clarification
by responding directly to this message in Resolution Center in iTunes
Connect.
For app design information, check out the following videos: &quot;Best
Practices for Great iOS UI Design&quot; and &quot;Designing Intuitive User
Experiences,&quot; available on the Apple Developer website.
You may also want to review the iOS Human Interface Guidelines for
more information on how to create a great user experience in your app.

How can I resolve this?
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.