You haven't said what you did with .renderingMode(), but you need something like this:
Swift:
var imageConfig = UIImage.SymbolConfiguration.init(scale: (isCompact ? .medium : .large))
if #available(iOS 15.0, *){
imageConfig = imageConfig.applying(UIImage.SymbolConfiguration.init(hierarchicalColor: .tintColor))
imageConfig = imageConfig.applying(UIImage.SymbolConfiguration.configurationPreferringMulticolor())
}
rtnImage = rtnImage.withRenderingMode(.alwaysTemplate)
rtnImage = rtnImage.withConfiguration(imageConfig)
SwiftUI;
Image(uiImage: UIImage(systemName: getIconName(iconId: iconId))!)
if #available(iOS 15.0, *){
.symbolRenderingMode(.multicolor)
}
