I found errata between Arduino IDE's pin definition andon-board silk indication on ULTRA Zero Color.

The mis-arrangement are found between D0 to D4 and details is drawn in the following image..

This difference can be aligned to "as written on board" if you have a chance to re-write firmware by Arduino.org's Arduino M0 (But it is not convenient since not main-stream so far..) Sorry inconvenient but please refer the attached PDF for your programming and prototyping.

Thank you,