The easiest, surest way to work a little of the hope of daffodils into your life is with the flowers themselves. They're at their best in big bunches. Try stuffing a couple of vases of daffodils, and placing them strategically around a room. Because they're so bright, they'll reflect back the light, brightening the space, even if you haven't yet gotten to your spring cleaning.
You can achieve this effect by using the color on accent pieces as well; a few daffodil yellow salad plates, bowls or cups, will do a lot to cheer up a kitchen or dining area. How about some new linen dinner napkins in daffodil yellow, or a hand towel and a bar of guest soap in the bathroom?
Can you use such a strong color for anything bigger than a breadbox? Sure you can, if you're careful about your approach. An entire sofa in this color would have to be judiciously balanced with carpet or rug, wall color, and accessories. Ironically, it might work better on a darker background than against a plain white wall. Imagine the daffodil yellow sofa situated against a wall that's painted a rich, deep red.
You can make sure you're using the color correctly by imitating the way it's used in nature. Think of the light green of daffodil stems, their rigid lines going all wavy in a clear glass vase filled with clean water. Green cushions on a sofa, or a rug in green and yellow, might be just the thing to bring down the brightness just a bit.
Even a whole wall could take a coat of daffodil yellow paint, as long as you think about what will sit in front of it, and what color the other walls are. While a softer, lemony yellow works well with white, daffodil yellow is too bright, and you'd most likely want to accent it instead with an off-off-white, eggshell, or cream to keep it from being too bright and cold.