Fly dressing needed

Hi to the group,
I'm just a new kid on the block could anyone give me a successful dressing
for an "orange blob" it seemed to be fishing very well the other day at my
local stillwater, the lake where I fish is stream fed, so during the "rainy"
season it tends to get somewhat coloured, and short of hitting the fish on
the head with the fly you have difficulty getting them to see anything that
doesn't stand out like roman candle in a cellar,
Tightlines.
John T