Spot the difference

When I looked out of the window first thing this morning I thought that something terrible had happened - the atmosphere was a strange dirty yellow colour. I turned on the news but there was no explanation and I wondered if my vision was failing. Eventually the colour seemed to return to normal and I thought no more about it until I saw the lunchtime weather forecast. Apparently the colour was caused by sand in the atmosphere blown up from the Sahara which stayed there until the rain washed it out. I should have taken a photograph.

Instead the photograph is of my cheap-as-chips Lidl orchid which I have had for a number of years now and which regularly blossoms. The intriguing thing is that the purple patterning varies from flower to flower to flower. Thank you Lidl.