How to use the co/style/colors.themed.mainAlt function in co

	background-color: ${({fallbackColor, theme})=>fallbackColor||themed.mainAlt({theme})};

title: {
					component: {
						name: 'component/logoText',
						alignment: 'center'
					}
				},
				...buttons,
				leftButtons: [
					{
						id: 'settings',
						icon: require('assets/images/settings.png')
					}
				]
			},
			layout: {
				backgroundColor: themed.mainAlt()
			}
		}
	}

static options() {
		return {
			topBar: {
				background: {
					color: themed.mainAlt()
				},
				title: {
					component: {
						name: 'component/logoText',
						alignment: 'center'
					}
				},
				...buttons,
				leftButtons: [
					{
						id: 'settings',
						icon: require('assets/images/settings.png')
					}
				]
			},
			layout: {