Did you know that primary colours are different depending on if you’re talking about art or about science? We all learned in school that red, yellow, and blue are the primary colours. But that is in art only. Replace yellow with green and now you have the primary colours of light. I’ll leave the artists and the scientists to fight that particular battle out and for convenience sake, I’m siding with the scientists today. Monochromatic is this week’s photo challenge and I chose three photos to fit the theme. They were all taken in Spain and each represent a particular colour – red, green, and blue – and they each were impacted by light in some way.