Creating animated glittering glow sign text effect

Start by typing your text using a bold font.

Duplicate the layer and hide it. Rasterize the text layer. From select menu select modify>>contract. Contract the selection by 2 pixels.

Press Delete to remove the inner fill area.

Double click the layer to open layer style window. Apply settings as shown.

Press Q to enable quick mask. From "Filter" menu select "Pixelate>>Mezzotint". Apply settings as shown.

Press Q again to disable quick mask.

Create a new layer and fill it with white color.

Ctrl+Click the hidden text layer thumbnail to get the selection. From select menu select modify>>expand. Expand the selection by 6 pixel.

Press Ctrl+Shift+I to inverse the selection. Press Delete. Repeat the above mentioned steps to create another mezzotint layer with different points.

Open animation window. For the first frame select the text layer. Double click the layer to open layer style window. Apply settings as shown.

Duplicate frame. Again double click the layer to open layer style window. Change color settings as shown.

Similarly create two more frames with different color settings.

Select the first two frames. Click tween button from animation window. Apply settings as shown. Repeat the same steps to other frames.

Select every alternate frame and hide the first mezzotint layer and unhide the second one.

Press Ctrl+Alt+Shift+S to save an optimized animated GIF.