[Toysrme]

The transmission guy is screwing you. If he flushes it, the fluid will be red until the fluid is 100% trashed, or worn out. He probably recognizes that yall need a rebuild & doesn't want to waste the time with it.

Other than that, I'm 90% sure yall have burned the first gear clutch & maybe the brake for it. You HAVE to stop driving an automatic transmission immediately when they start to slip. Otherwise kiss the clutches good-bye in a few min/few miles.
Drain the fluid out of the transmission & drop the pan.
If the bits are non-metallic, it's clutch particles.
Iron and steel are gear wear
non-ferrous particles are aluminum, brass and babbitt from bearings. A little bit is just normal wear, but if it's everywhere, or there's a lot of it, something is shot, or standing infront of the firing squad.





You can try flushing it yourself.

The filter is a little press metal unit with a small mesh screen on it. it's held up there by 3 * 10mm bolts. Check the mesh screen for particles.



Good luck with it! I hope it's just crappy fluid.