It sounds like you are using a DPD chlorine test where you compare the color of the sample to a standard which is varying shades/intensity of pink/red. High chlorine levels will bleach out DPD which explains the flash of pink turning to clear. The dark color after R-0003 reagent indicates high CC though the very high FC may be interfering with that somewhat.

You really should have a better test kit with a FAS-DPD chlorine test. If you don't have a Taylor K-2005 test kit already, then get the Taylor K-2006 which you can get from Amazon here. If you already have the K-2005, then you can get the Taylor K-1515-C kit from Amazon as well (same link as above, but then search All Departments for "Taylor K-1515". The FAS-DPD chlorine test will not bleach out (extra powder is added if you see a flash of pink) and it can measure up to 50 ppm and can measure with an accuracy of 0.5 or 0.2 ppm depending on sample size.

In the meantime, you can dilute the pool water sample with distilled water (even tap water would be OK, though would increase the reading a little but since it's so high already that's not a big problem) so if you use 1 part pool water with 4 parts distilled water, then you multiply the result of your tests by 5.