Boosting healthy food choices by meal colour variety: results from two experiments and a just-in-time Ecological Momentary Intervention

We walk through a simple idea with real traction. Can the colour on your lunch plate guide healthier choices when nutrient rules feel too complex? We break down two buffet experiments and a three week phone prompt in daily life, and we explain how colour, as a visual cue, shifted meals toward more vegetables while people said it was easy and pleasant. We also talk about why the effect faded when prompts stopped, and why fruit behaved differently in the lab and in the real world. You will leave with a clear, realistic takeaway you can try at your next lunch. And if you build health tools, you will hear how just in time prompts can turn a tiny habit into a practical nudge.