New Document & Colors

Make a new document sized 186 x 174 and set your foreground color to
#B4EF00 and background color to #89B903.

Gradient

Get the gradient tool out

And use the gradient type Foreground to Background

Now hold shift and click up above the canvas area and drag to below the canvas area

Few Details

Make a new layer (Layer > New > Layer) and make a 2px tall selection at the bottom of the document, with the whole width of the document, fill this with white

Now set the layer mode to Soft Light and the layer opacity to 50%

Text

Make text! I used Tahoma 30 pt color: #FFFFFF and a drop shadow

Add some more detail if you like, i dont really like the shine that I added, but anyway :)
Bright colors always do well for these sort of things, orange and light blue are good too