html5文件输入-如何使用javascript更改文件文本的颜色？

Question

I'm using an input type=file in a form, and after some javascript validation I'm changing the color to red if invalid and would like to change it back to black if valid.

However when I try to change it back to black, it stays red. How can I change this text color? Here is an screenshot example of the page after having used javascript to set the color back to black but the filename "2018-06-01-I...-3 cpds.csv" is still red:

Here is my code snippet:

<script>
function validateForm() {
    var dataFileInput = $("#dataFileInput");
    dataFileInput.css("color", "black");
    var dataFiles = dataFileInput[0].files
    console.log("dataFiles:");
    console.log(dataFiles);
    if (0 == dataFiles.length) {
        result = false;
        errorMessagesUl.append('<li style="color: red">please select one or more data files</li>')
        dataFileInput.css("color", "red");
    }
}
</script>
...
<input type=file id=dataFileInput multiple="">

Answer 1

A work around - add a click handler to the file input element to change the color to black when it is clicked:

$(document).ready(function() {
    $("#dataFileInput").click(function(evt) {
        $("#dataFileInput").css("color", "black");
    });
});