I am not a climber, but I have tried a wall or two in a climbing gym, and I managed to stuggle my way to the top, never sticking to one colour 😂. 
The look of a climbing gym is so interesting, I love the different oddly shaped holds decorating the walls, the chalk stains of thousands of hands attempting a route and climbers clinging to the wall all over the place, trusting their ropes and their climbing buddy to belay them. 
I wanted to draw a scene of people climbing, but the inside of an airplane hanger is a bit dull, and so these little people decided to make their gym in between some pot plants 🌱