It is extremely likely that your GH and KH test kits are not working. Those have definite limits on how long they will work after they are packaged. It also seems like you are using pH test strips, which are not known to be very reliable, instead of titration test kits. So, the first thing to do is to get good test kits, that have a manufacturing date within 6 months or so before today.
I have had GH test kits fail many times, but they always give some color change, just not that which they are supposed to give. KH kits have been more reliable for me, but those too can become out of date, and they still give a color change, just not the right one.