Sometimes cookies can appear more brown for a few reasons. One, you may have used dark brown sugar instead of light brown sugar or you eggs may have been a little too orange and bright yellow. The color of our ingredients can easily alter the tone of green in these cookies. Two, the type of matcha powder used could have been the culprit. All matcha powders are made differently and it can yield different colors. Three, if your oven runs warm or has "hot spots" it can cause your cookies to brown quickly or darker than normal.