One of these ducklings is not like the others...

Not the best pic in the album as the sun was a bit bright, but when I downloaded my photos today I noticed  something odd. 

One of these ducklings is a different colour - a much paler, more gold colour. I checked my other photos to make sure it was not just a trick of the light but they all show this distinctive difference. This is the only clutch of ducklings in this part of the pond so I wonder how this little one eventuated.