What is with authors who lean towards a more grayish skin color or like a dark tan skin color and their dick i

What is with authors who lean towards a more grayish skin color or like a dark tan skin color and their dick is complete light.

I’m a female but is it normal for your dick to be a whole different color. Like ML is grayish but his dick is completely light, and this isn’t the first time I have see authors do this.