Fix web devtools palette issue with most significant byte

On Wasm-4, palette colours are in the order `0xAARRGGBB`,
where `A` represents unused/alpha. On the web/css however, the order
is `#RRGGBBAA`. This meant that previously, if the most significant byte wasn't 0,
the colours in the devtool's palette viewer were garbled.

Author: majaha

devtools/web/src/components/palette/palette.ts

@@ -34,7 +34,7 @@ export class Wasm4Palette extends LitElement {
       ${this.heading && html`<h4>${this.heading}</h4>`}
       <div class="palette-grid">
         ${this.palette.slice(0, 4).map((color) => {
-          const colorHex = formatColor(color);
+          const colorHex = formatColor(color & 0xffffff);
 
           const shouldInvertColor =
             ((color & 0xff) + ((color >> 8) & 0xff) + (color >> 16)) / 3 > 128;