( This ( ( means ( they ( have ( no ( net ( color charge ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ means) (SBAR (S (NP (PRP they)) (VP (VBP have) (NP (DT no) (JJ net) (NN color) (NN charge)))))) (. .)))
This means they have no net color charge.
(ROOT (S (NP (JJ Iconic) (NNS compounds)) (VP (VBP have) (NP (DT a) (JJ net) (JJ neutral) (NN charge))) (. .)))