data visualization – how to visualize the lack of data for certain amount of time

Currently, I'm redesigning the line chart. Sometimes for the chosen time period, the user might lack data. I need to visualize it. Someone has any experience what would be the best solution? is it better to gray-out all field which lacks data or maybe gray-out just the period on the level equivalent to the available data? Does gray-out is a good solution? I thought adding another color might be misleading hence the dashes. Or maybe some other practices? what's most UX friendly?