Difference between light blue (1970) Spectraflame and ice blue Spectraflame.  Although it is hard to see in a jpeg photo, there is a distinct difference between the two colors.  In actuality, there is no light blue Spectraflame color.  Light blue cars are the result of a light spray, where there is less pigment in the paint than normal.  This is also present with other colors as well.  Ice blue was used in 1968 and early 1969 on production models.  It has also been found on late-1969 and 1970 prototypes, probably because they were manufactured in the early part of 1969.  Ice blue has a magenta tint to it, which can be seen when held up to a strong light.  Regular blue is a warmer color, and has no visible red hues.