@Jazzy
For centuries in the West, white has stood for purity and innocence (thus virginity).
A bride wearing a white dress is meant to proclaim that she is pure and innocent, she is a virgin. When my beloved and I were married, I also wore white. We weren't lying - but I admit, most couples at weddings do lie.
This is also why the tradition USED to be that brides who had already been married (they were divorced or widowed) did NOT wear white as their wedding.
Nonetheless, wearing white at one's wedding was not universal until fairly recently (it was popularized by Queen Victoria) ONLY because white is not a particularly faltering color for a Caucasion. It's been pretty universal since Queen Victoria wore it, she placing the symbolism above the reality that it wasn't a flattering color for her.
There's no rule known to me that the wedding dress must be something that won't or can't be worn again. But yes, the wedding dress is usually very elaborate and not suitable for regular wear, but that's up to the bride