On Blur field text field action not working immediately

To avoid such delays, The best way to change the property of a field object is with a custom format script, or in combination with a keystroke script or validation script.

The delay you're experiencing while using the current  onFocus/onBlur event method is because of how the data is precommited  before the trigger event; mostly during the typing activity(or copying and pasting from another source),  and how it will get fully commited after hitting the tab key, enter or clicking outside of that field, for example.

In the context of what you're trying to achieve, the triggering of the input data will behave similarily if you were employing a Keystroke event script; in both instances, the script requires that user enters data into that texfield, then the data is precommited as it is typed into the field, and finally it must be validated (or captured) before the triggering event fully commits that data.

Here's a good article, published by ACP Thom Parker, that explains better how that works:

• https://acrobatusers.com/tutorials/print/formatting_text_fields/

With that in mind, a script that will work well to change the appearance properties of a button widget, radio buttons, checkboxes, listboxes or dropdown menu objects,   will not behave in the same way for a textfiled object, specially if you have other scripts running custom calculating script that depend on what data is entered on that textfield.

If you want to enforce field property changes in real time and with no delays,  modify your current script to a custom Format script as shown below in my example.

This worked for me :

event.target.strokeColor = ["RGB",0.863,0.863,0.863]; 
event.target.borderStyle = 
border.u; 

if(event.value !== "" && (event.value !== "Internal")) {

event.target.textColor = color.black;

 } else {

event.value = event.target.defaultValue; 
event.target.textColor = color.ltGray; 

}