$\sim$3.1%. Thus the SOM photo-z (effectively based only on the seven color *Euclid*-like SEDs) performs nearly as well in terms of outlier fraction.

We have analyzed all of the outliers on a case-by-case basis. The majority (24/41; 59%) have *individual* (rather than SOM-based) photo-z estimates more in line with the measured redshift, indicating that the color cells they belong to have real redshift scatter. For nearly all of these sources, the measured dispersion in the 30-band photo-z’s within the relevant color cell is significantly larger than the median redshift dispersion per cell; in other words, these are sources that fall in more degenerate regions of the color space. The SOM can be used to identify these regions in a consistent way in order to either reject them in weak lensing analysis or direct extra spectroscopy at them to characterize the redshift distribution in those cells.

In addition, there are several other examples easily understood as Galactic stars (3) or obvious quasars/active galaxies (2), which are known not to have typical galaxy colors (total = 5/41; 12%). This process caught one mistaken line identification where our initial assessment of a MOSFIRE spectrum identified an isolated, narrow, strong line as \[\] $\lambda 