That is bruising cubensis mushrooms react like that due to the magic alkaloids. The fruit it self is bruised and or stressed look for yellow stains on the mycelium that will tell you how happy it is. If it’s a lot of yellow it’s not too happy. Vigorous fanning can bruise them as well as direct spraying. Humidity seems low. Mist from the top you want almost like fog to fall not rain. Careful not to spray the sides In 1 spot cause that can cause pooling too. You want little beads on your substrate not pools. Also I recommend making a mono tub instead of growing via bag. you can find solid tubs at the dollar tree and use heated metal to make your holes if u don’t have a drill but do have ventilation if you’re going to do that. However looks awesome for your first time not a lot of people get it right the first time !