Straight out of the camera, this scene appears to be shades of black and white.

When I reduce the saturation to zero in Lightroom, any hint of colour is removed and the image looks like this:

So what is the colour that tints the original image? I took the image into PhotoShop to take a closer look. With the colour selector dialogue box open, I can use the eyedropper tool to click on an area of the image to see what colour that pixel or pixels hold. To which colour do you think the grey shades are related?