This is a genus that includes the plants known as yellow loosestrife (but not purple loosestrife) and creeping jenny, so a loving of cool, damp conditions is indicated. Yellow is the most usual colour, but paler cream and pink are also possible.

Lysimachia ciliata 'Firecracker' has dark foliage, somewhere between plum and chocolate (there's a combination I never thought I would used, which provides a contrasting background to the clusters of bright yellow flowers. I personally don't like the colour combination, but people with less conservative tastes can rave about it.