Older games (ie- R-type, etc.) have a mostly orange spine label with the game text in black near the top, there's a band near the bottom portion of the spine label which is black with orange lettering with the TG-16 logo.
They shifted later on to labels that were mostly black. The game title on these is white, with the TG-16 logo also white just after it. The only color on these is a band of color just along the top. The color on these labels varies by genre. Theoretically, games of the same genre will have the same color label, but obviously this isn't always true... if you have older label games.
The game case thread on this forum has some pictures of reproductions of the latter type of labels if you need some pictures.