The next one is 'Gipsy Girl' , about as cheery a yellow as you will find. These aren't the huge crocuses, but rather small, early ones that do multiply freely.
Next is 'Lady Killer'. This has always been one of my favorites. I need to get a picture of this one open. It is all white on the inside with the deep purple shading on the outside of the petals. Another one sort of like this that I don't have yet is 'Zwanenburg Bronze' which is yellow with a brown/bronze color on the outside of the petals.
Last for this morning is 'Zenith'. The lighting in this picture isn't quite right, but these are lavender/blue with a white center around the yellow stamens.
With the number of crocus species available, you can have bloom over a rather long time in the spring (also fall if you get some of the fall blooming ones). When crocuses multiply, they form the new corm on top of the old one, so if you want to help them along with spreading around in your garden, you simply have to scratch the surface a bit after the foliage dies down to get to the new baby corms and replant them elsewhere. Crocuses will naturalize in a lawn, though you can't cut the grass until after the foliage is done if you want to keep your crocuses healthy. In a less formal space this really shouldn't be a problem because they are done close to the time when the first mowing of the season need to be done, at least in our climate.
More crocuses tomorrow - there are many more than I can ever write about.