The green (and also the blue, but less so) used by iMessage doesn't even meet the minimum contrast set by apple accesibility guidelines [1]

[1] https://medium.com/@krvoller/how-iphone-violates-apples-acce...

I just took screenshots of an Android green text bubble and the https://www.android.com/get-the-message/ site, and used Photoshop's eyedropper tool to compare colors. They're the exact same shade of green, #48dd8f.

But it's not just you! The green on Google's site looks visually brighter because the entire bubble is on a blue background. On iPhone, the green is normally on a white background.

Now, try setting your iPhone to Dark Mode in Settings, and you'll find that the green bubbles are still #48dd8f green and the text is still #ffffff pure white; it's harder to read on a black background, IMO.

No, not for me. I'm seeing much darker on my phone:

On the page: #75d993

In the video: #58bf5d

From my iPhone (iOS 15.6): #317332

Edit: scratch that! Apparently I turned on “increase contrast” years ago.

Could you upload a screenshot from your phone? Searching images online I see plenty that roughly match the colors they're using on the video/website, but none as dark as your iPhone. Reference: https://i.imgur.com/PlGjjQg.png

Maybe a personalization option?

Yes. Apparently I turned on the “increase contrast” Accessibility option years ago. I’ll be leaving it on.

The background color of the bubbles changes in a gradient kind of way, depending on their vertical position on screen. That may explain the disparity you're seeing.

It's objectively much worse contrast.

https://s.wsj.net/public/resources/images/B3-CB781_1017ST_2_...

My contrast tool says the blue contrast is 3.4:1 while the green is 1.9:1

The "increase contrast" green is both more readable and also just nicer looking. I don't know why it isn't the default.