You might still see yellow Yield signs in the wild ... Besides the generic triangle-shaped red-and-white Yield sign, you can also see other signs with the word 'yield' in them.

If you notice the yellow triangle, run the Power Troubleshooter ... If all the above methods fail to yield the desired results, try this method as a last resort. Before proceeding, shut down ...

Design-wise, a Yield sign comes in an upside-down white triangle with a red border ... Uniform Traffic Control Devices (MUTCD), it was a yellow with black Yield Right Of Way writing instead.