Q.My cactus is yellow from one side
I got this cactus few weeks ago amd i mistakenly kept it in the sun for too long and it turned yellowish from one side and other side is perfectly green, what am i suppose to do to fix this, please help. Is it a sunburn or something else??
From what you describe and the photo, it is quite likely that your cactus has been sunburned.
Here's an article that may help you with what to do: