hich common color usage mistake is illustrated in this chart? A scatter chart with colored dots plots actual hours versus estimated hours. The horizontal axis is labeled ?Estimated Hours? and ranges from 0 to 120 with tickmarks in increments of 40. The vertical axis is labeled ?Actual Hours? and ranges from 0 to 120 with tickmarks in increments of 40. The legend on the right side of the chart shows the color of the dot corresponding to different repair person. There are 20 repair persons. The dots show an increasing trend between (5, 5) and (90, 110). All data are approximate. a. Insufficient contrast b. Excessive color c. Neglecting colorblindness d. Unnecessary color