By default when using a for loop in bash the field separator is set to a space.

Example:

[[email protected] ~]$ for x in list:like:this; do echo $x; done  
list:like:this

One of the cool things about bash is that you can change this by setting a simple variable $IFS

[[email protected] ~]$ IFS=":"  
[[email protected] ~]$ for x in list:like:this; do echo $x; done  
list like this