Try some big 1/2 and 3/4oz white/chartreuse spinnerbaits with gold blades. Smallmouth love 'em, and the larger size and gold blades really stand out in the muddy water you described. Also, try some jerkbaits. I'm typically a lc pointer guy, but in muddy water, xraps have more action and seem to get more attention. The xr8s are a good all around size, but if you want to target smallmouth in the 2.5lb+ range, pick up some xr12s. They're going to seem too big, but trust me, they're not, especially in low vis conditions. Color wise, I would focus on glass ghost for slightly clearer water and hot steel for muddy water. Good luck!