annaw123-
From what I can see, your nitrite may have pegged the top of the chart. You should perform a dilution test to find out your actual nitrite level. Here's how I do it:
Take a clean cup, and fill the test tube with 5 mL of tank water, and then pour it into the cup. Then fill the test tube with 5 mL of distilled water, and pour that into the cup. Do that four times so that you have 1 part of tank water, and four parts of distilled water. Swirl the cup a little bit to mix it well, and then fill your 5 mL test tube from the cup. Perform your nitrite test as usual, and find the color on the chart. Then multiply your result by 5 to get the actual nitrite value (5:1 dilution). If your new test is still too high to read on the chart, then you may have to do a new test with 1 part tank water / 9 parts distilled water, and multiply the result by 10 (10:1 dilution).
I've found that even when my test result is still on the chart, those darker colors are difficult to discern, so I ended up doing the 5:1 test anyway when my nitrite was high.