Blue eye(s) indicate Splash, from my experience blue eye(s)s are more commonly caused by Splash than Frame. His facial marking also tells me he is Splash because it is lopsided, that's the way Splash likes to arrange white on the face/head. Even at it's most minimal, (usually a tiny patch of pink skin), a Splash facial marking will be off to one side of the nose by a nostril. His leg markings also look Splash.
Splash is an incomplete dominant gene which means the physical apperance is going to differ if the genes are heterozygous or homozygous. When it is in heterozygous form you get horses with markings that range from very minimal to the amount of white your stallion has and sometimes a bit more. When a horse is homozygous for Splash you get the unique horizontally arranged markings most commonly thought of when someone says Splash. As far as breeding heterozygous Splash horses, yes they may not have alot of color themselves but they can reproduce it quite easily if bred to another heterozygous Splash horse. I've seen many loudly marked homozygous Splash horses out of two horses that have very minimal white markings.
In advertising, people in general don't usually understand the term "heterozygous", and even less understand the concept of incomplete dominance and why this horse would be considered heterozygous and why he could reproduce Splash offspring, but more and more people are becoming familiar with the different terms used to seperate the "overo" pattern so some people probably would understand if you advertised him as Splash. If you are uncomfortable with that, advertise him as an Overo Rabicano or Rabicano Overo, however you want to put it. I've seen horses that were alot less "overo" looking than him being advertised as such.