Uneven cylinder temps. Need Insight

A few weeks ago I had issues getting my 84 gpz750 running and ended up finding the throttle partially open with the way the cable was hung up. Got great tips here from the forum. 

Since getting it running well, I’ve been focused on getting the rest of the odds and ends finished up. On Tuesday, I spent the day finishing up the tail light and turn signal wiring. At some point in the process I killed my battery, and got a new one Wednesday. I had been letting it run a minute or two every few days to keep things moving through the engine and carbs.

I had noticed the brand new header pipe on cylinder 2 was still chrome while 1 & 4 were straw colored and 3 is purple/blue at the first bend. 

When I fire the bike up now, it takes a bit longer to turn over and cylinder 2 header is cool to the touch after running a few minutes, while cylinder 3 pipe will be glowing red at the bend. The outside cylinders seem fine.

Before I start taking apart a finally assembled project, I wanted to ask for some guidance from the collective brain here. 

Bike hasn’t been ridden in 7 years but earlier this year I did a full tear down and clean of the carbs with ultrasonic cleaning. I have not vacuum synced the carbs either yet.

thanks for the help

Blue is hot, 
Brown/golden is correct
Metal colour is too rich or not firing. 
They look like delkevic single wall stainless down pipes. 
Question is why is 2 & 3 different. 
Likely blue is waaayyyyy too lean. 
Metal colour I doubt is not firing at all or if it is its waaayyyyy to rich. 
Remove the plugs and post electrode colour pictures. 

Yes, these are Delkevic pipes, with no miles on them only approx 10 minutes idle time.

Here are the spark plugs 1-2-3-4 from left to right. 

2 is the cold cylinder and 3 is the hot.

Difficult to say as those are presumably still choke rich mixture covered but No2 is def not firing. This'll give you an idea but it's not definitive for modern fuels.