I have a vague recollection that you can plant a certain combination of bulbs in a pot and this basically produces a cycle of different flowers that grow at different times, so you end up with pots that have year-round colour and come up every year without having to do much to them?
It is possible to have year round colour by planting bulbs and a few evergreens and maybe some trailing plants. It is not strictly 'no maintenance' because the soil will get tired and the bulbs and evergreens will be conjested eventually. If you put in a few annuals with the spring bulbs, you can pull them out when they have finished, leaving some space and an opportunity to feed and refresh the soil.
If you are not bothered about actual flowers, then small conifers, summer and winter heathers, circium and coleas make a nice display.