Nah, don't lower the opacity. The colors you chose to associate it with just doesn't really work well. Or maybe they did, but you could have just filterfucked the stock. I'd give it another go - with the same concept, but a different approach. The pentooling might not be the focal on purpose, but it's the only thing that was eyecatching in the signature. Also, pay attention to the lighting.
From what I think I've seen, I think you have done better.