OMG! that looks like a huge nuclear bomb explosion!
But No, it’s not an explosion or anything. That is just a cloud, look amazing though. It’s called a Thunderhead Cloud or a Cumulonimbus cloud, and the color which you can see in it is because of the sun rays falling on it.
it is of various types and may give the illusion of an explosion which looks pretty scary :
It can also be something pleasant like this:
Here is more on Thunderhead Clouds on Wikipedia: