By Harry Roberts
Harry Roberts is an independent consultant web performance engineer. He helps companies of all shapes and sizes find and fix site speed issues.
Written by Harry Roberts on CSS Wizardry.
N.B. All code can now be licensed under the permissive MIT license. Read more about licensing CSS Wizardry code samples…
If, like me, you frequently need the official1 Core Web Vitals colours for slides and presentations, here you go:
#09ce6b
#ffa400
#ff4e42
Good
rgb(9, 206, 107)
hsl(150, 92%, 42%)
hwb(150, 4%, 19%)
Needs Improvement
rgb(255, 164, 0)
hsl(39, 100%, 50%)
hwb(39, 0%, 0%)
Poor
rgb(255, 78, 66)
hsl(4, 100%, 63%)
hwb(4, 26%, 0%)
‘Official’ as in sampled from PageSpeed Insights and web.dev. ↩
N.B. All code can now be licensed under the permissive MIT license. Read more about licensing CSS Wizardry code samples…
Harry Roberts is an independent consultant web performance engineer. He helps companies of all shapes and sizes find and fix site speed issues.
Hi there, I’m Harry Roberts. I am an award-winning Consultant Web Performance Engineer, designer, developer, writer, and speaker from the UK. I write, Tweet, speak, and share code about measuring and improving site-speed. You should hire me.
You can now find me on Mastodon.
I help teams achieve class-leading web performance, providing consultancy, guidance, and hands-on expertise.
I specialise in tackling complex, large-scale projects where speed, scalability, and reliability are critical to success.