I live in Southwestern Ontario I am planting a 8ft tri color beach that I bought from the nursey , but it wasn’t tri color it was a green color , being a little puzzled by the color ,I asked the grower was it was so green and he claims it was due to a very dry hot summer ,and the tree didn’t receive the tlc it deserved because it was in the back with some other trees , where the watering wasn’t the best conditions , so I did get a warranty /guarantee on this tree because I am a little skeptical! Will this get the vibrant beautiful purple / pink leaves ? Grower claims yes!
Judging from your description, your specimen of tricolor beech (Fagus sylvatica ‘Tricolor’) with green leaves is puzzling indeed.
Do the leaves show any variation in colour, however slight it may be? A plant with normally colourful variegated foliage can sometimes fail to show all its colours. There are several possibilities. One is immaturity. Another is that it is still trying to adapt to its new location and unfamiliar climate. Yet another is excessive nitrogen fertilizer, which can promote vegetative growth at the expense of colouring. Insufficient sunlight can also be a factor.
Solid green leaves on a variegated plant is also possible when individual stems revert to species colouration. This phenomenon is frequently observed in wintercreeper (Euonymus fortunei), dogwood (Cornus alba), hosta, and weigela, for example. Such reversion could be due to environmental stress, or could be spontaneous (just as it first randomly mutated and developed variegated colouring). The isolated reverted stems, if left alone, can potentially overtake the entire plant, since they are more vigorous than the stems with mutated leaves.
Lastly, and perhaps the simplest explanation, is that the tree was mislabelled at the nursery.
You are wise to obtain a guarantee. We hope that, come spring, your tree will be showcasing the beautiful purple and pink variegation for which the tricolor beech is so famous.