Skip to content
Swizec Teller - a geek with a hatswizec.com

Make your things pretty with chroma-js

I once asked Shirley Wu how she makes all her dataviz so pretty: Baskerville font and chroma-js.

Chroma is a JavaScript library for dealing with colors. Read them, change them, make some delightful scales. It has changed the way I work.

I'm still new to the library, so I don't know everything. Here are some useful things I've found.

You can see them in action in this unfinished piechart showing how I spend money on transport. More on that next week.

Delightful color scales

Chroma color scales are designed to be delightful. You define two colors, and chroma-js finds the most pleasant path between them.

See the Pen Chroma basic scale by Swizec Teller (@swizec) on CodePen.

The quickest way to get some pretty colors going is to define an ordinal scale like this. Choose start and end points, say you want 6 colors, and pick the lch mode.

I'm not sure what lch mode means, but it creates nicer colors than the default rgb mode. They come out brighter.

You can create continuous scales as well. Add multiple points of reference etc. Great for encoding data with color.

Prettier hover effects

Chroma also helps you create prettier hover effects. Color effects in general, really.

You often see in web and dataviz design that people use opacity changes to create hover effects. You mouse over something and it becomes a little transparent so the white background shines through.

This works, but looks bland. It lightens the color. What you want instead is to make the color look brighter.

Chroma to the rescue with its color manipulation utilities.

chroma(color).brighten(2)

You can also saturate, desaturate, and darken. All useful effects if you find an excuse to use them. All better than just changing opacities.

Color brewer

If you're color challenged like me, then you can't go wrong with the color brewer utilities. A set of predefined colors that look great together.

That piechart above is made with the PuBu schema. chroma.scale("PuBu"). No need to worry too much, just go to color brewer, find a scheme you like, and tell Chroma to use it.

Happy coloring ๐Ÿ™๐Ÿป

Did you enjoy this article?

Published on March 2nd, 2018 in Front End, Technical

Learned something new?
Want to become a high value JavaScript expert?

Here's how it works ๐Ÿ‘‡

Leave your email and I'll send you an Interactive Modern JavaScript Cheatsheet ๐Ÿ“–right away. After that you'll get thoughtfully written emails every week about React, JavaScript, and your career. Lessons learned over my 20 years in the industry working with companies ranging from tiny startups to Fortune5 behemoths.

Start with an interactive cheatsheet ๐Ÿ“–

Then get thoughtful letters ๐Ÿ’Œ on mindsets, tactics, and technical skills for your career.

"Man, love your simple writing! Yours is the only email I open from marketers and only blog that I give a fuck to read & scroll till the end. And wow always take away lessons with me. Inspiring! And very relatable. ๐Ÿ‘Œ"

~ Ashish Kumar

Join over 10,000 engineers just like you already improving their careers with my letters, workshops, courses, and talks. โœŒ๏ธ

Have a burning question that you think I can answer?ย I don't have all of the answers, but I have some! Hit me up on twitter or book a 30min ama for in-depth help.

Ready to Stop copy pasting D3 examples and create data visualizations of your own? ย Learn how to build scalable dataviz components your whole team can understand with React for Data Visualization

Curious about Serverless and the modern backend? Check out Serverless Handbook, modern backend for the frontend engineer.

Ready to learn how it all fits together and build a modern webapp from scratch? Learn how to launch a webapp and make your first ๐Ÿ’ฐ on the side with ServerlessReact.Dev

Want to brush up on your modern JavaScript syntax?ย Check out my interactive cheatsheet: es6cheatsheet.com

By the way, just in case no one has told you it yet today: I love and appreciate you for who you areย โค๏ธ

Created bySwizecwith โค๏ธswizec.com