A Shiny creature is extremely rare, so it's simply a case of checking every one you are looking for - such as Magikarp - in the hope it will be a different colour. Often, the variation is somewhat ...

It only worked with a fishing rod, so unless you want a ton of shiny Magikarp the earlier setup ... of all the captured pokemon with an SD card and RTC. What did [dekuNukem] end up with for ...