Though the pixels carry cyan or grey color, the strawberries appear red to people.
This is because of a phenomenon called color constancy which is acquired by the brain over time based on our memory.
For example, no matter which color it may be, a human mind will always perceive a banana to be yellow and an orange to be orange in color. Likewise, our brain has a permanent memory of strawberries being red in color.
Therefore, irrespective of whether the image has red pixels in it or not, the strawberries in the tart appeared red to people.
In this process, the brain figures out the colors of the objects from its memory regardless of the color of the source.