You can't beat a single classic colour using Cinelli or Benotto tape, I like to colour match tape, cables and sometimes the saddle - although you are often limited with saddle colours.
I hate multi-coloured bar tape...it is very 80s retro, but in the worst possible taste!
For example, I have one bike painted pearl white with red cables and a red San Marco Rolls saddle with red Benotto bar tape on a Cinelli Giro d'Italia handlebar with the classic Cinelli 1a stem.
Oh, and to complete the ensemble; chrome Cinelli logo'd handlebar end caps.
Co-founder of a V-CC section, member South Eastern Road Club and owner of - 2005 Bianchi Reparto Corse (modern), 1985 Raleigh SBDU Pro Super, 1984 Raleigh LU Corsa, 1980 Allin Stan Butler Special, 1978 Ron Cooper, 1975 Bill Philbrook tourer, 2 x very early Roberts (mid/late 1960s), 1966 Raleigh Superbe Roadster, 1964 Allin Stan Butler Special Belgique, 1951 Hobbs of Barbican S/C, 1950 Hobbs of Barbican S/C, 1947 Hetchins Super Special, 1908 Centaur Featherweight. 1988 Specialized Stumpjumper.