Recently I had a large shoot where I photographed gymnastics teams as well as individual gymnast.  I had originally planned on doing my own printing with my Epson 3880, but with over 300 prints to make, I decided to go with a local professional lab called My Photo Pipe.  I have been using them since the film days and they were operated under the Color Genesis name.  They are located in Metro Atlanta and I can save money on shipping because they allow for local pick up.  They are a great lab, have a friendly and knowledgeable staff, and produce great products.  My prints came back and they were perfect.  Had the correct white balance, which was very important since the gymnast were posed on a white background.
Well somewhere along the way I did not upload all the image and I was 7 images short.  It was late Friday afternoon when I figured this out and I knew I could not get the images from My Photo Pipe in time for delivery on Monday afternoon, So, I thought I would try our local Wal-Mart.  This turned out to be a time consuming waste of money.  I uploaded images via their web portal and received a text in less than an hour saying they were ready.  I went to pick up the images and four of the seven had a magenta cast to them.  I asked the girl behind the counter why they printed that way and she told me it was because my files were that way.  Uh, I don’t think so, these files have perfect white backgrounds.  She then tried to say that the online ordering system would sometimes “mess up” the files and they would print poorly and I should bring them to the store and print from the kiosk.
I dutifully returned home to load the files to a usb drive and I also double checked the image files. They were correct in every way.  I returned to the store and uploaded the images through the kiosk and when the prints came out, three were ok and four were off color again, but some of the off color images were images that were fine during the first printing.  They young lady was very patient with me and tried to as helpful as possible.  I asked if the printer was calibrated daily and she promptly printed a nozzel check pattern and pronounced that the printer was calibrated.  Um.  Well no, that just means the print head is aligned and the nozzels are not clogged.  What about white balance.  She was totally lost, and you know what, it was not her fault.  She can only operate at the level of training she was given.  Which obviously, was minimal.  She was very polite and tried to help as best as she could.  The prints were totally unacceptable.
From now on, if I am not printing my own images, I will be printing with My Photo Pipe.  I ended up sending the files to them and picking up the prints on Tuesday and delivered the prints that afternoon.  Better to be a day behind schedule and provide a quality product.  Below is an approximation of the color cast.  They shredded the off color images so I didn’t keep them.  The left side of the image shows the color cast, the right sided of the images shows the correct color balance.  Keep in mind your monitor or screen you are reading from may or may not have the correct color balance as well.

Left side is color cast from Walmart and right side is correct color from My Photo Pipe