Two Colours Red

Since exploring the whole idea of colours and how they occupy and influence the space around them, I kept getting hits on the net for the artist Josef Albers. He's famous for his hundreds of paintings and prints of nested squares, Homage to the Square and his focus is on the optical effects created.

I used Adobe Illustrator to play around with this idea and in the first picture below I placed two squares of the same size and exactly the same colour red except one square is within two white lines and two grey lines. I think when you look at it, the red square closer to the centre looks brighter.