Please use the cc logo without white background colour (attached). As to the Trademark policies (https://creativecommons.org/policies): "You are not authorized to use any modified versions of our trademarks, except that you may use a different color for the CC logo and its background so long as the two colors chosen have a contrast ratio of at least 3:1."
#97b314 (button colour) and black have a contrast ration of 8.8.