Why is the white elastomeric roof coating turning yellow?
If the underlying substrate is asphaltic, especially a fresh asphaltic substrate. The yellowing is most likely due to asphalt bleed, which is simply low molecular weight asphaltenes leaching up through the coating. This discoloration will not hurt the performance of the coating. It is an unsightly aesthetic issue, but in most cases, the yellow color will bleach out and disappear over a few months.
