Just 2 CSS properties I discovered recently: caret-color and accent color.
1) CSS caret-color Property
Set the color of the cursor in input elements
input {
caret-color: red;
}
https://www.w3schools.com/cssref/css3_pr_caret-color.asp
Not supported in IE https://caniuse.com/css-caret-color
2) CSS Accent color Property
Accent color property sets the accent color for user-interface controls generated by some elements
accent-color: #67EADD;
<input type="checkbox"><input type="radio"><input type="range"><progress>
https://developer.mozilla.org/en-US/docs/Web/CSS/accent-color
Not supported in IE and Safari https://caniuse.com/mdn-css_properties_accent-color