Color code converter UI improvement

[rtewari056]

🛠️ Fixes Issue (Number) #895

👨‍💻 Changes proposed

Added custom styles to make the UI look beautiful.

✅ Check List (Check all the applicable boxes)

• [x] My code doesn't break any part of the project (Zero Octave-Javascript-Projects).
• [x] This PR does not contain plagiarized content.
• [x] My Addition/Changes works properly and matches the overall repo pattern.
• [x] The title of my pull request is a short description of the requested changes.

📄 Note to reviewers

Contributing under SSOC'22

📷 Screenshots

Before adding custom styles

After adding custom styles