Dark mode at Rohlik: keeping the strawberries fresh

At Rohlik we collected customer feedback all the time, and one request kept coming back: dark mode. I led the feature as both product designer and product manager, working with the development team to ship it across our web and apps. The palette was the expected part. The interesting part was the product photos.

Why people wanted it

The reason behind the request was very human. A lot of our customers shop, or plan their shopping, in the evening while putting their kids to sleep. They're lying in a dark room, scrolling through groceries, and they didn't want their phone lighting up the whole room.

So this wasn't about dark mode as a trend. It was about a real moment in our customers' day where the app was getting in the way.

The problem: food on a black background

When we started exploring, the first issue was obvious. Our product photos are shot on light backgrounds. Putting them on a dark UI looked wrong, and the alternative of showing products on a black background was worse.

Food is sold by how it looks. Picture a bowl of strawberries or a crisp apple on black. It stops looking fresh and delicious. For a grocery business, that's not a cosmetic issue. It goes straight to whether people want to buy.

What we tried

Our first idea was to keep the light photos and put a grey filter over them to tone down the brightness. It didn't work well.

We then tried a slight yellow filter instead. The images stayed light, so the food kept its natural, fresh look, but the warm tint took the edge off the brightness so the screen didn't shine as much in a dark room. That's the version we shipped.

Making it work in the system

On the technical side, two things had to happen.

A dark variant of our color palette. We adjusted the palette so every color had a dark mode counterpart, which let the UI switch modes consistently across web and apps.

A rule for images. Product images don't change between modes, so we created a rule that keeps images in their light mode version even when the rest of the interface goes dark. The yellow filter is applied on top of that.

Getting marketing on board

There was one more piece that wasn't purely design or engineering. To get nice rounded corners on images in the new UI, we needed marketing to start delivering PNGs instead of JPEGs. That meant onboarding the marketing team to a new way of preparing their assets, so dark mode looked right in the banners and visuals they produced, not just in the product catalog.

The outcome

I don't have numbers for this one. What we do have is the reaction: both the team and our customers were happy with it, and the most common response from customers was simply "finally, dark mode."

For a feature that started as one of the most requested items in our feedback, that's the result we were after.