Eli Fulkerson .com HomeProjectsRgb-color-gradation
 


RGB Color Gradation Function

Description:

This is a function that takes two normal HTML colors (for instance #CCCCCC; and #00FFFF;) and returns a specified number of color codes necessary to blend between them.

Platform:

  • no platform specific code, should work anywhere that has Python
  • Language:

  • Python
  • License:

  • This function is trivial. I am placing it in the public domain, do whatever you want with it.
  • Code:

    import string
    
    def make_color_tuple( color ):
        """
        turn something like "#000000" into 0,0,0
        or "#FFFFFF into "255,255,255"
        """
        R = color[1:3]
        G = color[3:5]
        B = color[5:7]
    
        R = int(R, 16)
        G = int(G, 16)
        B = int(B, 16)
    
        return R,G,B
    
    def interpolate_tuple( startcolor, goalcolor, steps ):
        """
        Take two RGB color sets and mix them over a specified number of steps.  Return the list
        """
        # white
    
        R = startcolor[0]
        G = startcolor[1]
        B = startcolor[2]
    
        targetR = goalcolor[0]
        targetG = goalcolor[1]
        targetB = goalcolor[2]
    
        DiffR = targetR - R
        DiffG = targetG - G
        DiffB = targetB - B
    
        buffer = []
    
        for i in range(0, steps +1):
            iR = R + (DiffR * i / steps)
            iG = G + (DiffG * i / steps)
            iB = B + (DiffB * i / steps)
    
            hR = string.replace(hex(iR), "0x", "")
            hG = string.replace(hex(iG), "0x", "")
            hB = string.replace(hex(iB), "0x", "")
    
            if len(hR) == 1:
                hR = "0" + hR
            if len(hB) == 1:
                hB = "0" + hB
    
            if len(hG) == 1:
                hG = "0" + hG
    
            color = string.upper("#"+hR+hG+hB)
            buffer.append(color)
    
        return buffer
    
    def interpolate( startcolor, goalcolor, steps ):
        """
        wrapper for interpolate_tuple that accepts colors as html ("#CCCCC" and such)
        """
        start_tuple = make_color_tuple(startcolor)
        goal_tuple = make_color_tuple(goalcolor)
    
        return interpolate_tuple(start_tuple, goal_tuple, steps)
    
    
    
    def printchart(startcolor, endcolor, steps):
    
        colors = interpolate(startcolor, endcolor, steps)
    
        for color in colors:
            print color
    
    
    # Example... show us 16 values of gradation between these two colors
    printchart("#999933", "#6666FF", 16)

    Source code without formatting