Something I noticed some time back has been emoji changing from color to shadow/black & white. below is some code I have used in my web applications to enable color emoji to appear as we expect them, like country flags.
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Noto+Color+Emoji">
<style>@font-face {font-family:Noto Color Emoji;unicode-range:U+1F1E6-1F1FF;}</style>