I am doing a rule-change proposal on this. I almost got eliminated at a combined test this weekend for using a dark, navy pad. I knew I was risking it - but afterwards, I went and checked the rules. There are none on saddle pads for eventing. I’ve checked the Canadian, American, and FEI rules. In fact, I could easily make the case that they are not permitted at all!
I have spoken with the TD and she agreed - she said we fall back to Dressage rules, which are white, off-white, grey, or black.
Well, screw that. I wanted to wear one pad for all 3 phases on a wet, rainy, muddy weekend, and navy is plenty conservative enough. I think the same colour scheme could apply to helmets, jackets, jodhs, and pads without any problem. Conservative light or dark colours - that would include grey, navy, brown (to go with tweed). The H/J set could probably even pull off muted pastels, I bet.
I haven’t found where in our rules we agree to default to the dressage rules, so that is my next step. (As maybe I can just have a rule change that says “we don’t default to dressage”.)
ETA:
-Canada: the eventing rules state they are to be read in conjunction with the General Regulations (not dressage). General regulations say nothing about saddle pads. Under the eventing dressage section, (D303), 1.2 reads, ‘The rules governing the Dressage Test shall be as laid down in the FEI “Rules for Dressage” except where specifically modified in the following respects.’
-USA: any situation not covered by the USEF eventing rules default to FEI dressage rules.
-FEI: I’ve found the FEI eventing rule that says “default to dressage rules” - in the preamble. But the dressage rules don’t say anything about pad colour.