In this updated CSS code, the following changes were made to enhance the visual appeal with more unique colors:

1. Text Color: The default text color for paragraphs, unordered lists, and anchor tags was changed from pure black (#000) to a softer dark gray (#3C3A47). This makes the content easier on the eyes while still maintaining readability.

2. Border Color: The border color of the left-image container was changed from black to medium blue (#3A6EA5), adding a subtle but noticeable accent to the design.

3. Button Background: The background color of the .btn class was updated from black to a vibrant coral red (#FF6B6B), making the call-to-action button more visually striking and attention-grabbing.

These color changes create a more modern, inviting design while maintaining the overall structure of the original layout.