How to solve type mismatch error ?

[kcvinu]

Hi all, I need to do some arithmetic ops like this. 
    
    
    var loopEnd : int = 300
    for i in 0 ..< loopEnd
      var r,g,b : uint
      r = cast[uint](c1.red + (i * (c2.red - c1.red) / loopEnd ))
    
    
    Run

But I am facing type mismatch errors. Which is the correct data type for these 
kind of ops. Please help.