Fishing a clear river on Saturday, I was aware that the new box of BB shot I'd bought were flashing brightly underneath the float. I usually use the Dinsmore shot, which are darker, but which still have a glossy finish. I just wondered if it mattered. I could see fish taking my loose-fed maggots but, however far upstream of the fish I cast my float, to minimise the splash effect, they disappeared when the hookbait went through the swim...

Rather than large shot like BB, why not try the equivalent weight in smaller sizes (hopefully that make sense )?
Using a smaller float (less weight) might also help.

I have had roach and dace "taking" the shot on the R Medway, thinking it was hemp, or tares, but smaller sized shot rarely spooks them.

Mouse dropping shot or the leadheads for artificial flies are ideal too. The cigar-like shape makes them hit the water surprisingly quietly and they tend to dull nicely once opened. No splashes and no shiny, giveaway shot.
I found them very useful for finicky Roach.