Water Color
First create a new image:

Width:        300 pixels
Height:      200 pixels
Mode:        RGB Color
Contents:   White
Create a new channel "Alpha 1".
Type some words on the middle of the image:
Right click on the "Alpha 1" channel and select Duplicate Channel.
Click OK, then
Go to Filter>Blur>Gaussian Blur.
Set the Radius to
4.2 pixels, click OK:
Select>Load Selection:
Choose "Alpha 1"

Expand By: 4 pixels, click OK:
(Depends on your text thickness)
Go to Filter>Texture>Grain:
Then Select>Deselect
Now go back to the background layer by clicking on it.
Select>Load Selection:
Load the "Alpha 1" channel.
Use the paint bucket tool to fill in any color you like, that's it!!