Can you read this in first attempt?
Not possible to read anything at all? Follow the guidelines bellow.
Close your eyes almost 90% so that you can actually read it, it's really cool.
The way this works is, when reading, your eyes and brain work together to take in information and make sense of what it is. One of the steps in understanding what it being read, your brain must see what the text is and what is the background. In this example the boarder of the text is the same color as the text itself, therefore your brain thinks the text is the background and so it tries to understand what the background says which it thinks is the text.
It is much easier for humans to read black text on a white background because those two colors are contrasted more than any other, like if there was black text on a gray background it would take longer to differentiate the two apart and thus take more effort to read what is write. It is also much easier for people to read black text on a white background because when reading black text the eye only needs to focus on what is presented, and in a case of white text on a black background it would be more challenging because the eyes and brain would need to work harder to distinguish what is not present in order to understand what is written.