change UI'e theme color to green

[aglassoforange]

Make the UI (Front-End) more colorful. Note that Front-End processes are done at the directory front-end.

The background color could be green.

[github-actions]

OpenHands started fixing the issue! You can monitor the progress here.

[github-actions]

An attempt was made to automatically fix this issue, but it was unsuccessful. A branch named 'openhands-fix-issue-17-try2' has been created with the attempted changes. You can view the branch here. Manual intervention may be required.

[github-actions]

An attempt was made to automatically fix this issue, but it was unsuccessful. A branch named 'openhands-fix-issue-17' has been created with the attempted changes. You can view the branch here. Manual intervention may be required.