In this Star Trek movie poster (my single favorite) there is a color spectrum, the Human is located in the section that includes among others the color red (Humans have red blood), the Vulcan in the section with green (theirs is green), and the Deltan is in the yellow section. Do you suppose that Deltan's possess yellow blood? Yellow blood does exist on Earth with certain types of sea life. The yellow coloration is due to a high concentration of vanabin. Yellow?