Pantone PMS 287 is known as Gentian Blue, PMS 287C, PMS 287M, and PMS 287U in various documents. The Gentian flower, the base for this colour name, can be blue violet, red, yellow, or white. The flag of Serbia contains a blue stripe defined as Pantone 287 C.
PMS 287 is a theoretical colour. PMS 287C is a specification for representing the colour on coated paper using specific Pantone inks. PMS 287M is the specification for representing PMS 287 on matte paper and PMS 287U is the specification for uncoated paper. Uncoated paper is washed out, colours appear lighter, and PMS 287U is probably a good starting point for presenting PMS 287 on cheap low contrast LCD screens. PMS 287C should be the starting point for good LCD screens and CRT screens. Matte paper diffuses light more than uncoated paper, making PMS 287M unsuitable for comparison to any screen.
PMS 287 has no equivalent in the modern Pantone TCX and TPX systems.
Pantone recommend representing Pantone PMS 287 in HTML as #003087 and #003087 is used for this paragraph.
Some colour charts recommend representing Pantone PMS 287 as CMYK 100/55/0/0. Gimp translates CMYK 100/55/0/0 to #0073ff and that is the colour used for this paragraph. The colour is a touch bright on screen and will darken when coated or printed on coated paper. The previous paragraph is a better representation for gloss paper.
HSV: 213%deg; 100% 100%
#003399 is a safe, but slightly lighter, representation of #003087 on devices with limited colour.
#0099ff is a safe, but slightly lighter, representation of #0073ff on devices with limited colour.
#0066ff is a safe, but slightly darker, representation of #0073ff on devices with limited colour.
Make up your own mind about the best screen colour to represent the colour you use for printed material, uniforms, signs, vehicles, and everywhere else. Test the HTML colour on a lot of screens including all the different Internet connected telephones.