Going through the Parenting and Weights, all of my control bones have a pink mesh indicating that they are not affecting the mesh deformation, except my Left Target control bone. It shows a blue mesh and I can’t determine why. The Deform box is unchecked for all of them.
General Q&A note
Help us all to help you.
Please give full screenshots with any questions. With the relevant panels open.
This can be done by Blender itself, via the ‘Window’ menu bar top left-hand side.
On that menu dropdown is ‘save screenshot’.
Also, if possible, include the lecture time and name/number that is relevant to the problem/issue.
I did a quick test to confirm whether the pink colour indicates that the bone is [a pole or target] in an IK chain, or it has Deform toggled off. Unticking Deform from the foot bone of my armature (the actual foot bone - not the target bone of the IK chain) resulted in all-blue colour in weight painting.
Based on that, maybe your IK setup isn’t symmetrized. Do both limbs move in the same way when you grab and move their IK targets in pose mode? Also, do the contents of the Bone Properties tab in their Inspectors look (symmetrically) identical?
I figure if one control bone shows pink in weight painting and its mirror partner doesn’t, it’s got to be something along those lines.