You used light DME, and you are thinking about using amber DME instead? Well, the beer would be darker with a hint of sweetness.
From Midwest's website about dry malt extract:
The malt extract products generally break down to 4 main categories. They are; "Extra Light" (generally used for pilsners or other straw colored beers), "Light", "Gold", or "Pale" (Three names demarking basically the same thing. Great as a fermentable base for most pale ales and some lagers, or used in conjunction with the amber or dark extracts and/or with specialty grains.), "Amber" (darker and with more residual sweetness than the "Extra Light" or "Light"), and "Dark" (Can be used for Porters and Stouts but needs to be infused with portions of chocolate and/or roasted barley to achieve varying degrees of those flavors, which are desirable for the style. The reason being that dark malt extract does not contain appreciable levels of these types of grain.)
No matter what kind of beer I was making (when I did extracts) I used light DME and used specialty grains for color and flavor.