Provide Omicron styles that match the LIGO color convention used to plot data from the different interferometers

• H1 <-> red
• L1 <-> blue
• V1 <-> purple
• K1 <-> ??? [worth checking with LIGO now to anticipate a style that could be used for KAGRA Omicron triggers in the future]
• [Not sure whether LIGO India already has its LIGO color]

Tagging @tito-canton for information.

Thanks!