Hey
Flippy is right to alter how the light from your sky shader appears is controlled by the q3map_sun keyword.
q3map_sun <red> <green> <blue> <intensity> <degrees> <elevation>
As you can see the first 3 digits are the colour of the light.
The next is how bright the sun will appear (though it doesn’t change the appearance of the sunshader)
The degrees is the position of the sun in the sky (A setting of 0 degrees equals east. 90 is north, 180 is west and 270 is south.)
The elevation is how high the sun is from the horizon.
As you can see from your shader your value for the intesity is very low try increasing it to around 150 - 200 ish, just try experimenting tweaking those values until you get the desired effect.
The q3map_sun is a point light source like a torch beam so anything that is in shadow will be dark.
The q3map_surfacelight command is a ambient light setting for the sky so thats another one you can tweak.
Hope this helps you out a bit.
Look at this link for more detailed explanations and shader keywords.
http://www.qeradiant.com/manual/Q3AShader_Manual/ch03/pg3_1.htm#mapsun
Cheers
<DJ>