First, create a new document that is 50x50 pixels. Make the background white.
Next, click on Filter - Noise - Add Noise. Use the following settings:
Next, create a new layer. Fill it white. Set the layer mode to Color. Select the layer filled in white and press Ctrl+E to merge the layer down.
Duplicate your bottom layer twice, so as there are three noise layers in total.
Select the second from bottom layer. Click on Filter - Other - Offset and use the following settings:
Now, click on the top layer and click on Filter - Other - Offset. Use the same settings as before but put +30 and +30 instead of +20 and +20.
You should now have three images that are slightly different to each other! You can either animate this or save each one as a new pattern for you to use when you make glitters!
To change the colour of this glitter fill, create a new layer above all of the layers and fill it with the colour you want. Then, set the layer mode to color.