Slow worm

I'd just popped out to check if my tomato plants needed watering when something long and silver caught my eye. It was a slow worm gliding smoothly over the pebbles surrounding the pond into the shrubbery. Then I saw a butterfly on the busy lizzies. It was very small with brown outer wings and bright orange on the inner surface. Any ideas what it could be? It was definitely a butterfly, not a moth, as it closed its wings while sucking nectar from the flower.