I require proof

Are US presidents allowed to wear ties that are not blue or red? I don't think I've ever seen Obama in a green tie, or a purple tie. Please send me a link HERE

UPDATE: Thanks to Adam's partially completed Ivy League education, he has been able to come up with the following:

http://www.huffingtonpost.com/2009/03/10/obamas-first-50-days-in-t_n_173195.html

Obama is not exactly a "green" president. Maybe this is a direct fashion attack against the nations of Bangladesh, Brazil, Jamaica, Libya, Macau, Mauritania, Nigeria, Pakistan, Saudi Arabia, Turkmenistan, and Zambia. We don't exaclty have fantastic relations with most of those countries. Oh wait, we don't exactly have fantastic relations with any country.