clouded

bedimmed, befogged, blackened, darkened, dim, dimmed, dulled, dusky, misty, murky, obscure, obscured, overshadowed

sunless

black, bleak, cheerless, dark, desolate, dismal, dreary, funereal, gloomy, glum, gray (also grey), somber (or sombre), sullen

overcast, rainy, stormy, thick

dirty, miry, mucky, muddy, slimy, slushy, turbid

smoky (also smokey), smudgy, sooty

filmy, milky, opaque