jquery - change color of fixed image after scrolling -

i want change color of simple icon white black - , - after amount of scrolling (due change in background color). see http://www.euimpact.com/erikverwey , scroll down - you'll see mean).

now i'm hoping in css/jquery somehow , have smooth transition, i.e. it'd possible image half black half white when crossing line.

but i'm guessing that's not possible, it?

would have switch different image @ scrolling point?

thanks lot!

i don't think possible have different colors on edge

but change color can use window scroll

a fiddle

$(window).scroll(function(){      if($(window).scrolltop()<800){             $('#fixed').css('background-color','yellow');       }else{           $('#fixed').css('background-color','white');     } }) 

i created fiddle div changes color on edge, have done complete mathematic, see issues. can play around fiddle find out exact values make working you.