Mystery Tetra

Hi, just wondering if anyone can identify this tetra, im pretty sure he's a tetra from his looks and behaviour. He's about 2cm long and 4 years old so fully grown.
I got him in a bag of chain loaches and was told they had no idea and he was bycatch
Cheers
Dan

That was my first thought too!
I compared him to the embers in the shop though and they just didnt look the same, shape wise or size, hes a tad bigger.
Also he was a pure bluey grey colour until he was about 2 years old then gradually started to develop the orange

Just found this photo from 3 years ago, doesnt look very ember ish eh
And even then he was bigger than the very orange embers in the shop, thats why i discounted him being an ember

And ive just rembered about the black line going from head to tail too,