Getting what I paid for - gut check please!

As @inagroove says the manufacturer is 100% in the wrong here.

You absolutely should return the item and get a full refund from them. 

If they try to resist, don’t take no for an answer.

I think you’re right not to blacken their name at this stage. Give them a chance to rectify the problems first. It may be a one off case with an otherwise fair manufacturer.

Sometimes when we fall foul of sharp practice we feel guilty as if we are at fault. This is clearly not the case here and you have genuine cause for complaint.

Conmen thrive because honest people feel gullible and are afraid to speak up. If this manufacturer gets away with it this time, he may try it again on someone else. 

"I don’t see any evidence of shadiness..."

"Upon pick up, I discovered the item’s faceplate and remote were a different color than what the manufacturer had indicated prior to purchase.  Upon getting it home, I learned by reading the materials that the warranty period had started at the date of manufacturer, not the date of sale, meaning the warranty period was about one-third the length it would normally be."

"The manufacturer is offering to replace the faceplate with the correct color for a fee.  He says the warranty "is what it is.""

"I do wish they had explained before I paid (which I had to do via bank transfer prior to pickup) that this was an ex-demo unit, not just an NOS older model..."

That  is shady...

But also, these are questions that should have been asked and answered prior to purchase.

I have never heard of a date of manufacture warranty. I had always assumed that the warranty started when you registered your product. At least now you’re gonna have an opportunity to see how the consumer protection bureau is working these days if you do decide to return it.   

                                                      gkelly

As far as I know, most consumer protections were eliminated by DOGE.

Sounds like you bought a demo unit, which is why the warranty had already started, so your gripe is with the dealer not the manufacturer. You got a great deal. I'm guessing the dealer would rather take it back than deal with you anymore.

"I don’t see any evidence of shadiness, just some sloppy communication"

@lousyreeds1 - You have received helpful feedback from people here with many collective years of experience with this stuff.  At the end of the day, we all make our decisions and live with the results.  IMO, you are being very generous to this vendor, as is your prerogative.  As I read through your description of the experience, my "red flags" kept popping up with my end conclusion being that none of the excellent vendors I have purchased from over many years would have practiced as you described.  Consider your comment, "I do wish they had explained before I paid (which I had to do via bank transfer prior to pickup)".  Who requires a "bank transfer" before you would be able to pick up a component?  Also, consider how all the things this vendor didn't explain to you ahead of time contributed to outcomes in their favor, not yours. 

@bigdoghoss - the consumer protection bureau primarily deals with financial issues such as regulating banks, lenders, and financial companies, and enforces laws and practices related to mortgages, credit cards, and loans.  I doubt they would have offered any tangible protection related to the timing of when an audio equipment vendor decided to initiate a warranty period or whether the vendor accepts a return.