[OS X Emacs] can't save color themes in aquamacs

[Ted gao]

Hi All,
I am using Aquamacs 1.9 on an i7 15'' macbook pro. recently, I tried to change the color theme by M-x color-theme-select. I was able to change the color theme in the current buffer. however, when i use options->save options to save setting. after I restarted the aquamacs, the old theme is back again. has anyone experienced this issue before? if so, can you tell me how can i save it? Thank you very much!
Chuan