A red bracelet can be your own reference to remembrance, but its color won't tell everyone the same story. Start with a design you'd like to wear and decide what the association means to you.
Choose the bracelet and any poppy separately. You may want to wear both, one or neither. For an event or an official role, follow the organizer's instructions first.
Red and black as a personal choice
If you like the combination, compare a red band with a small black detail against the clothes you'll wear. You might prefer a mostly black bracelet, a brighter red or something you already own. Choose the balance you prefer; its meaning comes from your reason for wearing it.
The Royal British Legion's poppy guidance says whether and how someone wears a poppy is a personal choice. You can make that decision separately from choosing wrist jewelry.
In Canada, Veterans Affairs Canada gives its own advice: the left lapel where possible, or close to the heart when there is no lapel. It also describes commemorative occasions outside the annual remembrance period. If your bracelet is a personal reminder, you can keep that association beyond the November events.
A colored band and a campaign symbol are different
A plain black bracelet doesn't automatically represent a black poppy campaign. Nor does a white or purple bead mean you've donated to or support a particular group. If you want to refer to a specific symbol, read what its organization says about it first.
For example, the Peace Pledge Union describes its white poppy as remembering all victims of war, challenging the glorification of war and expressing a commitment to peace. BlackPoppyRose explains its symbol in relation to the contributions of African, Black, West Indian, Caribbean, Pacific Islands and Indigenous communities to wars, revolutions and rebellions. Those are the organizations' stated meanings, not meanings attached to every bracelet of the same color.
For purple, Animal Aid describes its own campaign history: it launched a purple poppy for animal victims of war in 2006, then discontinued that poppy in 2015. So check who's behind a symbol today; a similar color doesn't mean the same appeal.
You don't need to judge another attendee's views from a wrist color. If you want to explain your own choice, give the explanation you mean; you don't owe anyone a longer personal history.
If you want to support an appeal
If a bracelet is sold as supporting an appeal, look for a clear statement on the listing of which organization gets what. A poppy-red color, a charity's name in the description or a photo next to a collection box doesn't tell you where the money goes. You can always donate directly through the organization's own website instead.
The awareness bracelet guide covers color meanings and charity claims in more detail.
Wear the piece you can leave alone
Try it with the actual coat or sleeve and check that it stays comfortable while you move. A familiar bracelet may be easier to leave alone than something you've just bought for the occasion.
If the bracelet has a memorial inscription, decide how visible you'd like it to be. The guide to wearing a memorial bracelet covers that private choice.