trouble changing gradient on buttons, can't get bright enough
 

I'm having trouble changing colors to match my site on some of the tiny buttons. For example, I'm trying to change the colors of the buttons/lastpost.gif and other arrow buttons to a bright orange, but when I apply the gradient without a blend mode it goes over the edge of the button. When I apply it trying out various blend modes, it always comes out too dark, like this:
http://www.icecreamnewyork.com/forum...s/lastpost.gif
when I'm really trying for a brighter color like this:
http://www.icecreamnewyork.com/forum...n/post_new.gif
can anyone advise me as to how to get the colors bright enough without getting rid of the shading and depth of the original?