Yellow is definitely the color of the month in my garden, and I suspect in yours.
In much of the Northern Hemisphere, March is the month where every garden worthy of the name, does have some daffodils in bloom.
Each of us has our own personal method by which we confirm the onset of spring. For me it is when my ground-hugging yellow aconites bloom.
I am now digging big wide round holes and placing lots of bulbs of different sizes and bloom times all together at differing depths.
Ruth Arthur wrote a poem about the juxtaposition of the last vestiges of winter and the optimistic signs of spring. Read it on this Focus on Flowers.
Everything you could ever want to know about the crocus... on this Focus on the Flowers.