orange = positive/concave up
purple = negative/concave down,
(linear) The deeper the color, the greater the rate of change search query is in the last 7 days. [1st derivative]
(quadratic) The deeper the color, the more concave up/down the trend of search query is in the last 7 days. [2nd derivative]
(each day is average of past 7 day of raw data)