Giovanni Boldini (December 31, 1842 - July 11, 1931) was a masterful Italian painter who is known mostly for us stunning and elegant portraits.
He painted with a beautifully fluid style and amazing use of color to render form in his paintings. In fact, a Time magazine referred to him as the "Master of Swish" in 1933 due to his flowing style. His style appears to be similar to that of John Singer Sargent.
Much like Sargent, Boldini's portrait paintings have a beautiful realism yet a painterly quality. Up close, you can see all his strokes of color and nothing appears overdone.
Below are some of Boldini's portraits. Observe his use of color in the paintings and the overall color harmonies. In many of his portraits, he used small bursts of vibrant color amongst areas of grays and browns to stunning effect. Also, take note of how well Boldini balanced the color temperature in the paintings.
Whilst Boldini is known for his portraits, I find his paintings of other genres to be equally stunning.