Paint code for 1971 Bonneville.

Yo Woody, Model Season started in August. There should be a 2 letter prefix irrespective of model on frame:
First Letter was month:
Jan A
Feb B
March C
April D
May E
May F
June G
July H
Aug J (NO I)
Sep K
Oct L
Nov P
Dec X

Second letter was Year:
C - Aug 68 to July 69
D - 69 70
E- 70 71 ( NO F)?? Could be printing mistake of course
G - 71 72
H - 72 73

Colours:

71 Tiger Gold and Black Petrol Tank, gold mudguards black stripes. White Lined. Black frame air filter boxes and side panels.
72 Tiger Gold tank top and mudguards. White Tank lower and mudguards stripe. Black lined. rest as 71

Yer maybe know this already but it might help others. All info from Triumph Twin Restoration by Roy Bacon

 

Try http://www.rsbikepaint.com/en-us/colours.php#makeid=154&modelid=4362&prodyear=1971

If you ring them they will probably be able to offer suggestions/ send sample piccie, and try looking at all the Bonnie colours on drop down list.