I actually don't mind Dundas either. It's got a bit of a warm two-tone colour, so it's not fully in-your-face with its garish bile-ness as it could be. Ultimately I think Wellesley is one of worst. It's blue, it's cold, and it's befitting of a prison washroom. On the whole I don't mind because it's obviously just a station, and not supposed to be a fancy community hub like we're building them now. But I think the colour at platform level is worsened by the bus bay overtop. Dark, dingy, dirty is all I can say about it.
On the point about Vitrolite. It may not have existed at the time, but we've made some advances in glass/porcelain strength over the years. NE of Peterborough is one of the world's largest nepheline syenite deposits and a mine which is very much active in extracting it. Not all that sure how, but I guess the stuff is used by industries to strengthen their glass products. Had it been incorporated into Vitriolite at the time, perhaps we'd still those tiles in our stations.