Pantone PMS 287

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 and 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.

CMYK 100/55/0/0

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.
CMYK: 100/55/0/0
HSV: 213%deg; 100% 100%
HTML: #0073ff
RGB: 0,115,255

#003380

#003380 is another suggestion for representing Pantone PMS 368 in HTML.
CMYK: 100/64/0/45
HSV: 218° 100 55
HTML: #003388
RGB: 0,51,141

#003591

#003591 is a suggestion for representing a similar colour, Pantone PMS 661, in HTML.
HTML: #003591

Safe colours

#003399 is a safe representation of #003380 on devices with limited colour. #003399 is named Dark power blue in some colour schemes including Wiki colours.
HTML: #003399

#0073ff is a safe representation of #0073ff on devices with limited colour.
HTML: #0073ff

Conclusion

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.