This guide will allow you to create a dynamic and modern effect that changes the color of a section while scrolling the page using pure HTML, CSS, and JavaScript.

The goal is to create a section whose color changes progressively based on the scroll position, creating a more dynamic and engaging web experience.

This effect is particularly useful for:

• Landing Page
• Portfolio
• Hero Section
• Creative Sites
• Product Presentations

The final result will be a smooth transition between different color tones while scrolling, making the browsing experience more interactive and visually appealing.

Prerequisites

• Hardware: A computer with internet access
• Software: A code editor (e.g., Visual Studio Code, Sublime Text)
• Browser: Google Chrome, Mozilla Firefox, or Microsoft Edge
• Basic Knowledge: HTML, CSS, and JavaScript

PROCEDURE: Creating a Section with Dynamic Color During Scroll

By following this step-by-step guide, you will obtain a section whose background color changes progressively while scrolling the page.

Step 1: HTML Structure

• Create a section twice as tall as the browser window height with a central title.

Changing Colors
Scroll the page to see the effect.



New Section
Keep scrolling the page.

Step 2: CSS Styling

• Set a basic style for the page.
• Define the section with the color-changing effect.
• Apply position: sticky to the content to keep it visible while scrolling.

 {
margin: 0;
padding: 0;
box-sizing: border-box;
}
body {
font-family: Arial, sans-serif;
}
.color-section {
height: 200vh;
background: rgb(40, 80, 200);
position: relative;
}
.color-content {
position: sticky;
top: 0;
height: 100vh;
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
text-align: center;
color: white;
}
.color-content h1 {
font-size: clamp(50px, 8vw, 100px);
margin-bottom: 20px;
}
.color-content p {
font-size: 22px;
}
.content {
min-height: 100vh;
padding: 120px 10%;
background: #fff;
color: #222;
}
.content h2 {
font-size: 50px;
margin-bottom: 30px;
}
.content p {
line-height: 1.8;
}

Step 3: JavaScript

• Calculate the scroll percentage.
• Progressively modify the RGB color values based on the scroll position.
• Use the progress variable to interpolate the color components.

window.addEventListener('scroll', function() {
const colorSection = document.querySelector('.color-section');
const scrollPosition = window.scrollY;
const sectionHeight = colorSection.offsetHeight;
const progress = Math.min(scrollPosition / sectionHeight, 1); const red = Math.floor(40 + (215 - 40)  progress);
const green = Math.floor(80 + (150 - 80)  progress);
const blue = Math.floor(200 + (55 - 200)  progress); colorSection.style.background = `rgb(${red}, ${green}, ${blue})`;
});

Step 4: Customization

• Modify the starting and ending colors to create different transitions.
• Add more shades for a more complex chromatic effect.

Verification and Troubleshooting

After implementing the color-changing effect during scrolling, it is important to verify correct operation and resolve any issues.

Functionality Test

• Scroll Verification: Scroll the page to ensure the section's background color changes progressively.
• Color Check: Verify that the transition colors are as desired and that the transition is smooth.
• Responsiveness: Test the behavior on mobile devices and tablets to ensure the effect works correctly on smaller screens as well.

Problem Resolution

• Color Not Changing: If the color does not change while scrolling, check that the JavaScript code is correctly linked and that there are no errors in the browser console.
• Non-Smooth Transition: If the transition is not smooth, ensure that the background property in CSS is set correctly and that there are no conflicts with other styles.
• Positioning Issues: If the content does not remain fixed while scrolling, verify that the position: sticky property is correctly applied to the .color-content class.
• Section Height: If the effect is not visible, check that the height of the .color-section is sufficiently large (height: 200vh).

This approach allows you to transform a simple vertical movement into a visual element capable of making the browsing experience more engaging.

• No external libraries or plugins are required.
• The effect is easily customizable.
• It can be combined with other scroll-related effects.

Try experimenting with different color combinations and animations to create unique and modern experiences.