Red has been turned to white, now how do I turn blue to black?

I have written a new loop next to the first loop but it does not work.

    if image is all blue
        red = 0x00
        blue = 0x00
        green = 0x00

Update: I have written this code and all I get is an error message.

            if(triple.rgbtBlue < 0xff0000 || triple.rgbtBlue > 0x000000)
            {
                triple.rgbtRed = 0x00;
                triple.rgbtBlue = 0x00;
                triple.rgbtGreen = 0x00;
            }