solutions - What is the reason for the blue color of an ammoniated electron?

I am quoting a line from a book regarding reactivity of alkali metals with liquid ammonia.

The blue colour of the solution is due to the ammoniated electron which absorbs energy in the visible region of light and thus imparts blue colour to the solution

Now my question is:

1. 
   

   How does the independent electron get excited (without transitional levels)?

   
   
   


2. 
   

   Why do salts of particular alkaline metal always have a fixed flame color if transitions of electrons can be from any energy level.

   
   

   (I am asking this question based on my knowledge of school where we only studied transitions among hydrogen like species)