Open a new document. Type your text using bold type (it gives a better effect), and don't forget to Render the Text (Layer> Type> Render Layer).
 

Now to get those ants marching press the Ctrl key and click on the active layer in the Layer palette to load the selection.

Go to Channels and create a new layer (it should come up as Alpha1), fill the selection with white. And then duplicate the layer (it should come up as Alpha2).

Press Ctrl+D to deselect and Gaussian Blur the Alpha2 (Filters> Blur> Gaussian Blur) to a Radius of 3 pixels.

Go to layers and click on the text layer to make sure its active. Next go to Filters> Renders> Lighting Effects. Use the default style and in 'Texture Channel' select Alpha2.
 

Next go to Curves (Ctrl+M) or (Image> Adjust> Curves) and do the setting as shown. Create a W or a M. It's best to play around in those 2 shapes, till you get the right shade you want.

To apply color, go to (Image> Adjust> Variations). Make sure the 'Midtones' is ticked. Now apply the selected color or combinations of colors to get the right effect.