Get colors from a pattern

Unfortunately, We can not access patterns information via script. However, we can read some info from Illustrator's document files directly.
Here is a sample data of patterns.

%AI3_BeginPattern: (testPattern)
(testPattern) 0 0 96.0603962102068 96.0603962102068
%_0 A
%_0 Xw
%_0 Ae
%_u
%_4 As
%_0 1 0 0 0 Xy
%_0 J 0 j 1 w 10 M []0 d
%_0 XR
%_0 96.0603962102068 m //move to current point that pattern rectangle
%_96.0603962102068 96.0603962102068 L //line to next point
%_96.0603962102068 0 L //line to next...
%_0 0 L //line to next...
%_0 96.0603962102068 L //line to next...
%_n
%_/ArtDictionary :
%_1 /Bool (AIPattern_Editor_Backing_Tile_Rect) ,
%_;
%_
%_1 Ap
%_4 As
%_0 O
%_0 0 0 1 k //c0,m0,y0,k100 fill-process ink
%_65.8276568462916 48.0301981051034 m //move to ellepse start point
%_65.8276568462916 38.2009330571509 57.8594631530559 30.2327393639152 48.0301981051034 30.2327393639152 c //rightDirection, next leftDirection and next anchor to make curve.
%_38.2009330571509 30.2327393639152 30.2327393639152 38.2009330571509 30.2327393639152 48.0301981051034 c //curve to next
%_30.2327393639152 57.8594631530559 38.2009330571509 65.8276568462916 48.0301981051034 65.8276568462916 c //curve to next
%_57.8594631530559 65.8276568462916 65.8276568462916 57.8594631530559 65.8276568462916 48.0301981051034 c
...

Do you mean without dragging the pattern swatch onto the artboard? How would you want them saved? Graphic Styles? Swatches? Symbols?

The first thing I'd do is drag the pattern swatch to the artboard, save as Symbol and delete instance. Then parse the elements in the symbols.