A component can change its category altogether with <svelte:component>. Instead of a sequence of if blocks…

{#if selected.color === 'red'}
    <RedThing/>
{:else if selected.color === 'green'}
    <GreenThing/>
{:else if selected.color === 'blue'}
    <BlueThing/>
{/if}

…we can have a single dynamic component:

<svelte:component this={selected.component}/>

The this value can be any component constructor, or a falsy value — if it’s falsy, no component is rendered.