It's all right to blame the source. Imagine half a population having grayscale screens. Would you pick colors that map to the same shade of gray? I guess not, s

It's all right to blame the source. Imagine half a population having grayscale screens. Would you pick colors that map to the same shade of gray? I guess not, so why would you pick colors and thickness that can be mistaken on so many setups? In this case it doesn't matter, as it's obvious which line is which.