Updated Arduino App to new theming system

Signed-off-by: Jan Bicker <jan.bicker@typefox.io>

arduino-ide-extension/src/browser/components/arduino-select.tsx

@@ -16,7 +16,7 @@ export class ArduinoSelect<T> extends Select<T> {
             control: styles => ({
                 ...styles,
                 minWidth: 120,
-                color: 'var(--theia-ui-font-color1)'
+                color: 'var(--theia-foreground)'
             }),
             dropdownIndicator: styles => ({
                 ...styles,
@@ -45,7 +45,7 @@ export class ArduinoSelect<T> extends Select<T> {
                 // `primary50`??? it's crazy but apparently, without this, we would get a light-blueish
                 // color when selecting an option in the select by clicking and then not releasing the button.
                 // https://react-select.com/styles#overriding-the-theme
-                primary50: 'var(--theia-accent-color4)',
+                primary50: 'var(--theia-arduino-selectItemHoverBackground)',
             }
         });
         const DropdownIndicator = () => <span className='fa fa-caret-down caret' />;