I thought you mean the down / right arrows in the horizontal menu bars
To change the color of (only) the arrows in the page next/previous navigation you'd have to do this inline as those arrows don't have their own class.
At A. Theme Options
-> Previous/Next Navigation
-> "Older Page" link on MULTI post pages
change the content of the text field to i.e.
See next post for additional info on how to make this work
Older Entries <span style="color: #123456">»</span>
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