Creating Likert Scale graph

I need to create a SINGLE BAR Likert scale chart with a range from 1 to 6 (low scores in the color gray progressing to black for high scores) and then plot four groups' average scores along that scale (i.e., so Excel will place a tickmark and the group's score on the correct place on the scale - e.g., 2.84 for group 1 will fall somewhere between 2 and 3 on the Likert bar chart). I am imagining a one bar horizontal chart with graduated colors from gray to black and individual scores plotted along it. I need Excel to recognize the scale range and the placement of the groups' scores on the correct place on the one bar scale. Help!