The phrase "mix-up of" is correct and usable in written English.
You can use the phrase when you are describing a jumbling or confusing combination of things. For example, "I was confused by the mix-up of colors and shapes in the picture."
The telltale mix-up of names is hardly surprising.
"It's an architectural mix-up of Elizabethan, Jacobean and William & Mary.
1.35pm: "Reminds me of the hilarious bedroom mix-up of the Hon William Hague," says @misssfitt.
Software programs can compute the quickest solution to any given mix-up of the cube's faces.
And we have a growing mix-up of secondary education between free schools and academies and local authority maintained schools.
Due to a mix-up of frequencies, an oration from a nearby funeral service briefly sounded down the loudspeakers at North Marine Road yesterday.
He argued that Islamists like those in the Muslim Brotherhood who embraced elections committed a "mix up" of Western and Islamic systems.
One of them should have gone to Garcia but, due to a mix up of names, it went to Chaplin, along with Larry Russel and Ray Rasch.
Volcanic alert level systems (VALS) of widespread use at volcano observatories result in a mix up of scientific assessments and social, economic and environmental evaluations that prevent clear, unambiguous communication.
In this paper we identify two main challenges with current ecosystem services classification systems: i) the inconsistency across concepts, terminology and definitions, and; ii) the mix up of processes and end-state benefits, or flows and assets.
"It was a mix up of telegrams but sadly the good news didn't last long," he said, "Less than 24 hours later, they sent a second letter reporting the loss of the ship and the rescue of six hundred survivors".
