graphical slider for iphone

Looking for code for iPhone to be used to replace the slider What I want - is a bar from 0 to 15 in increments of .5 with 2 buttons - one a + (plus) and one a - (minus) touching buttons will move the bar some bars will have a max value but the bars will always go to 15 If the max is reached then the remaining bars will change color For example - if a task has a max of 9, the bar would show green for 0-9 and will show red for 9.5 - 15 I would also like for a way to allow the end user to set the good / bad colors from either the bundle settings or thru a plist / view page simple app - one bar only to help me understand the different ways to accomplish this --? I currently accomplish it using individual images, but would like to reduce the app size. and have it handled using Quartz??? Currently the bar length is 210 X 40 pixels - so each segment is 7 X 40 pixels