can ~/.signature deal more than one signature?

[bing yu <byu@xxxxxxxxxxxxxx>]

hi, maybe this question is addressed quite often,but i still need help
scince i can not find answer by google.

usually in my .muttrc: set signature="fortune|"   but i want creat my own.

1. can i write a ./signature file in which there are more then one
signature i can quote them in random order?  if so, how to seperate
different ones in .signaure. And how to *set signautre* in .muttrc(
i find this line by google:  set signature="cat ~/.signature && signify|" is 
this right?) 

2. is the any signautre like *fortune* that can output some ascii picture
such as the following?

 ("`-/")_.-'"``-._
   . . `; -._    )-`'\  ,/`)
   (v_,)'  _  )`-.\   `-'
  _.- _..-_/ / ((.'
 ((,.-'  ((,/

3. can i let my signature in ./signature have different color?  here i
mean those who receive my mail on other mail client can see diffrent
color like some HTML mail.


any hint is welcome. 
thank you, have a nice weekend.

-- 
this is my signature (from ~/.signature)