Last week, I attended a local meetup that featured two presentations. One of the presenters displayed his slides with black background and green text. He said he loved the console aesthetic, so he designed his slides in a traditional console style (think about The Matrix). Perhaps in an attempt to further reduce eye strain during his normal workday, he also turned on the blue light filter in his display settings.
Unfortunately, the venue’s monitor was a bit old. We could barely read the screen with his settings. One of the event helpers tried switching off the lights to see if it improved visibility. It did help, but the photographer could no longer take photos. Combined with other technical issues and the presenter’s style, the audience soon lost interest.
This experience made me reflect on my own preferences. I alway enable dark mode on my devices and apps to dark mode to reduce eye strain. As an Agile coach in my previous company, I occasionally gave presentations, and my default choice was slides with a black background. I never had visibility issues because I always presented in a well-equipped meeting room.
One of my old presentation slides, presenting EBM.
But giving a public or semi-public presentation is a different story. Sometimes, you have no idea about the display quality at the venue. A low-quality projector screen is even worse. Try doing a code review on one with dark mode – you won’t be able to read anything.
There is an exception – when your presentation is virtual, and everyone is watching on their own computer screen. Whether you use a light or dark them doesn’t make much difference. However, your display preference doesn’t always match the audience’s preference.
For example, you might be using a 42" monitor to present your codebase in 4K resoultion, but your audience could be viewing it on a 24" HD monitor. They won’t be able to read anything. Similarly, not everyone is comfortable watching a yellow-tinted screen. Some may find it distracting and lose focus.
This was my first time attending a semi-public presentation at a meetup. Unfortunately, I didn’t learn much from the presenter’s content, but I did learn an important lesson – play it safe when preparing presentation slides. Using a light-coloured background with high-contrast text ensures readability, no matter the venue or setup. You never know where or how your slides will be used.
I have my own approach to slide design. I seldom fill my slides with words – I prefer not to rely too heavily on slides at all. Presentation slides help enhance your talk visually, but what really matters is your content. Any unexpected issues can seriously affect the audience’s experience. It could also distract them from your presentation – they might start judging your slide design rather than focusing on the content itself.
Yes, a bright screen without a yellow tint can strain our eyes, but are you going to present a two-hour lecture? If it’s just a 30-minute presentation, it’s totally fine.