( ( ( ( Turn off ) or ) ( block ( the ( blue light ) ) ) ) . )
(ROOT (S (VP (VP (VB Turn) (PRT (RP off))) (CC or) (VP (VB block) (NP (DT the) (JJ blue) (NN light)))) (. .)))
Turn off or block the blue light.
(ROOT (S (NP (DT A) (JJ blue) (NN block)) (VP (VBZ appears) (ADJP (JJ blue) (PP (IN in) (NP (DT the) (NN sunlight)))) (SBAR (IN if) (S (NP (RB only) (JJ blue) (NN light)) (VP (VBZ is) (VP (VBN reflected) (PP (IN by) (NP (DT the) (NN block)))))))) (. .)))