Apply your graphic style to a shape. Change the style, color, or whatever, to what you require and then drag it back into the Styles Palette. It creates a new style. It's the same process as editing symbols which does have an entry in the help files.
I was trying to avoid having to re-select each object with the original style applied and apply a new style to each one. I was hoping that by editing the styles (in this case by simply changing the colour) that each object with the style attached would be updated. Is this possible? I used to be able to do this in FreeHand with a 'Find/Change' command to graphic elements, including colour, so thought there must be a similar method in Illustrator.
Yes, you can do that. If you have edited your style and dragged it to the Styles Panel then select an instance of the style you wish to change, go to Select>Same>Style and this will select every instance of that style. Then click on the new style you just created to change them all. There are other ways (using the eyedropper for example) but this one is relatively easy.
Otherwise, select all the instances of your style and use the Appearance Panel to make the changes. Actually, err....that's probably quicker!
But it may feel better to see the changes in one case before using it everywhere, even though Undo is your friend.
Thanks very much for your help - sorted!
I was hoping that by editing the styles (in this case by simply changing the colour) that each object with the style attached would be updated.
1. Apply the original Graphic Style to an object.
2. Edit the Appearance(s) of the object as desired.
3. AltDrag the object and drop it onto the original Graphic Style.
That will edit the original Style, rather than creating a new one. Other objects to which the original Style was already applied should update accordingly.