At sunset, where the ground is in darkness, the lower portion of the thunder cloud was red, and the top white, against a blue sky background, an airplane passed between the viewer on the ground and the cloud. During the time, the cloud internally lights up from in-cloud lightning.
<a href="//commons.wikimedia.org/w/index.php?title=User:Docfirerock&amp;action=edit&amp;redlink=1" class="new" title="User:Docfirerock (page does not exist)">Docfirerock</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>