Override variable in variables.scss not working until refresh occurs

Hi I have a toggle in a component. I want to set the on color from the default to yellow.

I modified the variables.scss as follows:
$toggle-ios-background-color-on: yellow;

If I than launch my app via ionic serve it does not change the color from the default.

If I change the override color after I have done ionic serve it will perform a live reload and the color will change. Or I can do a refresh in chrome and the color change will occur.

I have also tried moving the settings change to the components .scss file with the same result.

Any ideas as to what I am doing wrong?

Perhaps you need to refresh your browser cache?

See: https://robferguson.org/blog/2017/11/13/theming-your-ionic-3-app-part-2/