Mitsubishi ws-65905 color tube needed

the screen image is in a greenish shadow. the images have sharp edges from a focus/clarity stand point but the color over the entire screen is dark. my uncle who i got the tv from researched the problem with some local technicians and was told it was a weak color tube. problem has gotten much worse since i brought it to maryland from florida. our tv repair guy, after doing all the convergence/alignment things said it was a part dealing with the focus but later after changing this part out changed his assessment to needing the new green tube. the screen image is in a greenish shadow. the images have sharp edges from a focus/clarity stand point but the color over the entire screen is dark. my uncle who i got the tv from researched the problem with some local technicians and was told it was a weak color tube. problem has gotten much worse since i brought it to maryland from florida. our tv repair guy, after doing all the convergence/alignment things said it was a part dealing with the focus but later after changing this part out changed his assessment to needing the new green tube.