Changing the size of the grassbuffer

I'm just looking to tinker with the grass colorizer between biomes and increase the blending zone, I am looking in ColorizerGrass and it looks like it is fed an array of blocks but am not sure where to look to modify the amount of blocks the blending occurs over. 

Here is the default ColorizerGrass just so you can see

public class ColorizerGrass
{
    /** Color buffer for grass */
    private static int[] grassBuffer = new int[65536];

    public static void setGrassBiomeColorizer(int[] par0ArrayOfInteger)
    {
        grassBuffer = par0ArrayOfInteger;
    }

    /**
     * Gets grass color from temperature and humidity. Args: temperature, humidity
     */
    public static int getGrassColor(double par0, double par2)
    {
        par2 *= par0;
        int i = (int)((1.0D - par0) * 255.0D);
        int j = (int)((1.0D - par2) * 255.0D);
        return grassBuffer[j << 8 | i];
    }
}