lerpColor(c1, c2, amt)
Calculates a color or colors between two colors at a specific increment.
The amt parameter is the amount to interpolate between the two values where 0.0 equals the first color, 0.5 is half-way in between and 1.0 equals the second color. N.B.: Both colors must be either CMYK or RGB.
Type: function
Parameter(s):
- c1 {Color}:Input color 1. 
- c2 {Color}:Input color 2. 
- amt {Number}:The amount to interpolate between the two colors. 
Returns:
- 
    {Color}:
 Interpolated color