lack contrast , are murky and are frequently too dark to be decipherable . 
(ROOT (S (NP (NN lack) (NN contrast)) (, ,) (VP (VP (VBP are) (ADJP (JJ murky))) (CC and) (VP (VBP are) (ADVP (RB frequently)) (ADJP (RB too) (JJ dark) (SBAR (S (VP (TO to) (VP (VB be) (ADJP (JJ decipherable))))))))) (. .)))
(ROOT (S (NP (NN ) (NN )) (, ) (VP (VP (VBP ) (ADJP (JJ ))) (CC ) (VP (VBP ) (ADVP (RB )) (ADJP (RB ) (JJ ) (SBAR (S (VP (TO ) (VP (VB ) (ADJP (JJ ))))))))) (. )))