You mentioned in a comment on another answer that outdoor photos of overcast scenes also look okay. If only the bright outdoor scenes have weird color balance, I suspect those frames were overexposed.

The density of a negative corresponds roughly linearly to the intensity of light, but only within a certain range. At the extremes, the density response becomes non-linear. If a negative is badly over- or under-exposed, color balancing the printer for the mid tones tends to produce wild colors in the highlights or shadows. It's practically impossible to get a good looking print, so the technician may not have even bothered to try on those frames. A digital lab may be able to apply a non-linear correction, but this is not possible on older printers where the operator just dials in cyan, magenta, and yellow exposure.