Southern League colours

May 28, 1906
The colours of the Southern League teams are: –
Brentford: blue and gold stripes;
Brighton and Hove Albion: blue and white stripes;
Bristol Rovers: black and white stripes;
Fulham: white;
Luton: Cambridge blue jerseys;
Millwall: navy blue;
New Brompton: black and white stripes;
Northampton: claret and white stripes;
Norwich City: blue and white halves;
Plymouth Argyle: green and black jerseys;
Portsmouth: pink and salmon;
Queens Park Rangers: green and white stripes;
Reading: dark blue and white stripes;
Southampton: red and white stripes;
Tottenham Hotspur: white shirts;
Watford: red, yellow and green stripes;
West Ham United: red and blue vests, white knickers.
(Source: Athletic News: May 28, 1906)

Watford F.C. 1905-06 (from historical football kits website):