Photo from NASA / Solar Dynamics Observatory
These are a series of images taken of a massive solar flare that occurred on Monday the 24th of February. The images are of the same flare at the same moment but differ in that they are taken at different wavelengths. Kind of like if you took a photo of a butterfly at different wavelengths and one photo displayed all the red on the butterfly, another green, and so on. But these images are of light at smaller wavelengths than we can see, and at a much higher energy.
The wavelengths are given on the images in Angstroms or 10^-10 m, 100 million millionths of a metre. The light we normally see ranges from 3900-7000 Angstroms and these pictures are taken at wavelengths shorter than this. 1600 Angstroms is in the near UV spectrum, while 94 Angstroms is in the extreme UV. The actual colours shown in this photo are false and are just used to help visualise the images better.
While this is the largest recorded flare for this year, the scientists at the Solar Dynamics Observatory state that the effects were minimal here on Earth due to the location of the flare on the surface of the sun being directed away from us. No pretty aurora from this ejection.