I used the online analysis tool to calculate means of usual hours worked by occupation in one small state (Oregon), using 2016 fiveyear ACS. The output shows shades of blue and red, with some cells uncolored. The legend shows corresponding Z statistics.
I have two questions:

What does uncolored mean? The legend shows light blue as <0 and light red as >0. But the blank cells don’t seem to be EXACTLY zero, which would be a value that equals the sample mean.

How can I describe red and blue shades in terms of statistical significance? As I understand it, you’d want a Zstat of +/1.65 to be 90 percent confident the mean of one cell is different from the overall sample mean. In the online output, very light blue corresponds to a Zstat between 0 and .5, or less than half of one standard deviation. But it’s tempting for me to attach SOME meaning to this result, based on your use of a color vs. no color.
Thank you in advance.