they are one and the same as far as I am aware. they refer to Erythronium de-canis. I have pagoda which is a yellow flower, some plants have silvery green markings, some non and some brown. I think of the leaf colouration a bit like human skin colour. many variations but the same species non the less.
I also have white beauty which is a smaller flower and white but again variation in the leaf.

I have posted a few photos of my erythroniums on my page. I have never heard of them being called trout lilies so thank you for expanding my knowledge. Another plus for GOY members helping each other.

Both names refer to any member of the Erythronium genus, which is neither a violet or a lily, of course. E. dens-canis is the European Dogs Tooth Violet. There is a wonderful range of mottled leaves across the whole range of Erythronium.

Thanks everyone. I have some just about to flower, so I will photograph them soon.