DHL planes are hard to miss. The bright yellow livery they carry is not one that you are going to miss easily. They may not have the wide reach of FedEx or UPS in the US but Boeing Field is a regular stop for them. The 767 is one of their staples, much as it is for all express carriers. They also make use of the 757 which pleases me given my fondness for the first airliner I ever flew on.
Evening light is the best for getting a DHL jet since the yellow positively glows when the low sun gets on it. I had a bit of traffic during this visit and these are the jets I saw.