A pilot using an iPad had a track deviation because of a communication error and reported the electronic Foreflight track overlaying the Victor airway prevented him from reading the airway number.

Narrative

We were filed GUY DHT TAFOY AEG. East of OTTO we were given an amended clearance; 'Direct to OTTO then V16 (we thought) ABQ AEG.' We repeated that clearance and had no comment from Center. When we looked at our low altitude chart (using electronic charts) we saw that V12 was a course between OTTO and ABQ. We noticed that V60 also went from OTTO to ABQ. We did not clarify with Center the correct airway; but since we had written down V16 we thought we had misunderstood and the correct clearance was V12 so we proceeded on V12 after crossing OTTO. When the Controller queried us about the course; we confirmed we were on V12 and were told we were cleared via V60 not V12. We altered course and intercepted V60 and continued. One contributing factor is that the electronic chart overlays the course on the airways and covers up the airway numbers so I was having a problem reading the airway number and thought I had it correct when in fact it was not. I am going to ask ForeFlight to consider changing the course line to a transparent color rather than a solid color. To prevent recurrence I will ask for clarification if I don't see the numbers I am expecting even if the Controller is very busy.