Interesting facts you should consider when lighting an oil painting:
When collecting older paintings you have to consider that the majority of paintings painted before 1860 were made to be seen in daylight with a northern light source. Artists used a preferred northern light source to paint the painting itself.
Illuminating them with a carefully chosen placed fluorescent light will cause some distortions, mainly in the blues, which can create an impression of hard edges in adjacent colors.
The same painting illuminated with tungsten light will suffer more serious distortions in the relationship of its color values. In these conditions paintings will tend to take on a hard look, as if seen on a computer monitor.
The best choice to illuminate an older painting is one that mimics that of natural light.