Why is my gasoline purple?

[bczoom]

I completely drained the bulk tank today out of the drain that's at the very bottom of the tank.
First 10 gallons, I got rust (expected) but then some weird colors, especially towards blue. It then ran clear for 40+ gallons.
The last 3 gallons out of the tank came out purple/blue. See attached pic. That's a brand new perfectly clear piece of PVC.
Why is it purple?
I don't think I've run Sta-Bil in 10+ years. I switched to SeaFoam years ago but haven't used that in at least 5 years.
I ran all the drained fuel through a Mr. Funnel to remove any water and debris but the purple remains.
Why?

 

[Big Dog]

Barney pissed in the tank, he does it all the time!

 

[Lenny]

I completely drained the bulk tank today out of the drain that's at the very bottom of the tank.
First 10 gallons, I got rust (expected) but then some weird colors, especially towards blue. It then ran clear for 40+ gallons.
The last 3 gallons out of the tank came out purple/blue. See attached pic. That's a brand new perfectly clear piece of PVC.
Why is it purple?
I don't think I've run Sta-Bil in 10+ years. I switched to SeaFoam years ago but haven't used that in at least 5 years.
I ran all the drained fuel through a Mr. Funnel to remove any water and debris but the purple remains.

It might be a good idea to do an internet search on this because there is some information.

 

[bczoom]

It might be a good idea to do an internet search on this because there is some information.

I did look but the results had to do with gas stoves (not the same).
Thought I'd tap into the brain trust on this awesome forum.

 

[FrancSevin]

Colors of the rainbow in you gas tank?
Obviously, your gas tank is gay.
Don't be prejudiced.

 

[Lenny]

I did look but the results had to do with gas stoves (not the same).
Thought I'd tap into the brain trust on this awesome forum.

I googled "can gasoline turn purple color" and a few things came up.

 

[Kevlar]

Not sure where you are, but here in Manitoba farm gas and diesel is died purple, possibly some of that in your tank? But seems strange it would run clear for a bit then purple, you’d think it would be mixed up better than that.

 

[bczoom]

I may have figured it out.

Many years ago, I used both the red (regular) and blue (marine) Sta-bil additives, just to get the cans off the shelf. Red+Blue=Purple.

Being as the cans were probably past the 2 year shelf life of the additives, they may not have thoroughly mixed with the gas and then settled to the gas at the bottom of the tank.
I've e-mailed the company to see if they agree with my conclusion. If they agree, I also asked if it's OK to burn it "as is" or if there's too much additive and it needs diluted with untreated gas.

 

[bczoom]

Well, according to Sta-Bil, it's not them. Here's their response.

"Based on the info provided, STA-BIL products would dissipate within the fuel causing no change in fuel color. As long as STA-BIL was used by the treat rate recommended on the packaging, it would not sink to the bottom of the fuel tank."