Personal Guidelines For Dressing For Emotionally Significant Events.

No matter what kind of emotionally significant event you’re attending be it a wedding, graduation, christening, funeral, baby shower, or something else entirely  the most important contributions you can make are to show up and show you care. Very few people are going to pay close attention to what you’re wearing and will be more affected by your demeanor and participation than your clothing and accessories.
However, bearing that in mind, emotionally significant events are some of the few for which you should aim to blend in. I don’t generally encourage anyone to conform, purposely dull, or invisibilify themselves, but my experiences have led me to believe that events such as these call for clean, plain, unobtrusive dress. If you wear your finest fancy dress to a wedding and dress up more than the organisers, you’ll feel crappy. If you pile on the statement jewelry for a funeral, you’ll feel conspicuous. Many emotionally significant events are about honoring SOMEONE ELSE, and if you keep your clothing and accessories chic but subdued, you will allow the process of honoring to continue smoothly.
In terms of specific guidelines, here are my personal opinions:

Unless directed to do ankara, black or gray is perfect  for funerals: I am extremely lucky to have attended only a handful of funerals, so I’m no expert. But my honest opinion is that you should wear something plain, black or gray, the end. The main thing is that you show up, give hugs, and support the bereaved. But unless you are attending a service for which festive dress has been suggested as a way to honor the departed, just do black or gray. Dress, suit, blouse and skirt, blazer and slacks, anything office appropriate should work.

No white, cream, or ivory at weddings: It may seem like an antiquated rule, but weddings are attended by plenty of etiquette sticklers and I just don’t see the point of rocking the boat. No one has a wardrobe full of nothing but white, cream, and ivory. Just wear something else.

Avoid loud patterns: There’s nothing wrong with a simple floral, some tasteful plaid, or a chic geometric, but garish patterns should be avoided. For instance, I’d feel comfortable wearing this or that to an event, but not this or this. Use your judgement and feel free to deploy patterns that you adore, but steer clear of truly loud, attention-grabbing ones.

When in doubt, wear jewel tones: Nearly everyone can find a jewel tone that flatters her skin and hair, and these rich-yet-subdued shades are ideal for broadcasting respect and sophistication.

Simple hair, makeup, and accessories: Obviously, this doesn’t apply to evening events or anything that specifies black tie. But for a funeral, day wedding, or anything of that ilk, keeping your grooming and adornments clean and classic will help further the goal of broadcasting honor and respect.
Again, I am no expert in these matters and I’m sure there’s plenty I’ve overlooked. So I turn it to you: What are your personal guidelines for dressing for emotionally significant events? What do you avoid? Embrace? Ever perpetrated a gaffe? How did you handle it? Any older rules that you think should be discarded?