1) Custom input colour using the accent-colour property.
You can use the CSS property accent-colour to change the colour of your input element, and yes you can use input[type="inputType"] for selecting a specific input element based on its type.
<input type = "checkbox">
<input type = "radio">
<input type = "range">
CSS
input[type="checkbox"]{
accent-color:lime;
}
input[type="radio"]{
accent-color:red;
}
input[type="range"]{
accent-color:blue;
}