Hi!
A total of 12 astronauts have walked on the moon. They were all part of NASA Apollo missions.
20 Jul 1969 - Neil Armstrong, Edwin "Buzz" Aldrin
19 Nov 1969 - Charles (Pete) Conrad, Alan Bean
05 Feb 1971 - Alan Shepard, Edgar Mitchell
30 Jul 1971 - James Irwin, David Scott
21-23 Apr 1972 - Charles Duke, John Young
11-13 Dec 1972 - Harrison Schmitt, Eugene Cernan
NASA is now looking to return to the moon, and even eventually to send astronauts to Mars. Check out
http://www.nasa.gov/mission_pages/exploration/main/index.html Over the course of billions of years, yes, the Sun changes colors -- but you may also be thinking of different-colored Suns because many solar observations are taken using filters, which select out certain colors. Some of these are visible colors (e.g., red, green...) but sometimes they are filters sensitive to light we can't see, like X-ray and ultraviolet. When such images are taken, they are often represented with different colors that we can see -- these are called false-color images. See
http://son.nasa.gov/tass/content/emspec.htm --Sarah