ionic add color name to theme code example

Example 1: ionic color

<ion-button>Default</ion-button>
<ion-button color="primary">Primary</ion-button>
<ion-button color="secondary">Secondary</ion-button>
<ion-button color="tertiary">Tertiary</ion-button>
<ion-button color="success">Success</ion-button>
<ion-button color="warning">Warning</ion-button>
<ion-button color="danger">Danger</ion-button>
<ion-button color="light">Light</ion-button>
<ion-button color="medium">Medium</ion-button>
<ion-button color="dark">Dark</ion-button>

Example 2: ionic change css propery

// use Shadow Parts
// https://ionicframework.com/docs/api/toast#css-shadow-parts
ion-toast::part(button) { 
    background: red;
    border-radius: 14px;
}