Acid stain concrete stain too dark

yea, that walnut will get real dark on you quick. For whatever reason that color burns the strongest, im sure your patio is damn near black now. the rule of thumb is you can always go darker, much harder to lighten it up. Muratic wont work, espically since its sealed. you'll just create a whole new problem. you prob have to live with it or do an overlay. you can do textured overlays then come back and redo your coloring. that starts at about $6,7 sqft

I've had to strip a sealer on my back porch one time. It is not fun. You may have to do that, then try the muriatic acid. Good luck