There were several insignia whites in use during WW II and they differed between camouflage and non-camouflage aircraft. The correct color for camouflage aircraft in 1943 was color No. 601 lusterless insignia white. This white is not a stark white and is similar to the off white used to paint most Cessna aircraft. The difference in shade is only apparent when placed next to a pure white. Here is the color in moderate and bright white against a pure white piece of paper, 601 was pure flat with no gloss, the insignia blue is also flat.