The Mego Micronauts Time Traveler is the most common Micronaut figure, but comes in a lot of variations of color, chest plates and packaging. For the US market, the Time Traveler was released in four transparent colors:

And four solid colors:

They also came with one of four different chest plates that might be in silver or gold color.

Like most micros, there were Mego, Hour Toy, Grand Toys and international packaging versions.

Time Travelers from the Interchangeables line, while similar to the transparent Mego figures, came in more saturated colors. Below you can see a comparison of several different TTs, including the markings on the back that will help you differentiate between models.