Could you sugest a way to make textbos like that more visible just when it's disabled?

Maybe change the CSS class "text-muted" or "br-light light"?  I think the CSS disabled  selector is your friend here.

That code does not appear to have anything disabled but if you want to style a disabled control you can do this

input[disabled] {
   color: #444;
}

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Here's a link: http://www.w3schools.com/cssref/sel_disabled.asp

Here's an example:
https://iconoun.com/demo/temp_efuerte.php

<?php // demo/temp_efuerte.php
/**
 * https://www.experts-exchange.com/questions/28977971/Could-you-sugest-a-way-to-make-textbos-like-that-more-visible-just-when-it's-disabled.html
 *
 * http://www.w3schools.com/cssref/sel_disabled.asp
 */
error_reporting(E_ALL);

// CREATE A SMALL HTML SNIPPET USING HEREDOC NOTATION
$htm = <<<EOD
<style type="text/css">
input[type="text"] {
    background: green;
}
input[type="text"]:disabled {
    background: orange;
}
</style>

<input type="text" />
<input type="text" disabled />
EOD;

echo $htm;

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code does not appear to have anything disabled

True, but we can't see the effect of JavaScript.  The input controls may get disabled conditionally, based on client actions.

The code is disabled in jQuery after modal is opened:

$('#view').on('show.bs.modal', function () {

	$('#view input').prop("disabled", true);
	$('#view select.dropdown').attr('disabled', true);
	$('#view .select select').prop('disabled',true)

});

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It's ok  to be disabled, just need to be more visible.

I'm founding the better place to put this .css code since this is a Codeigniter view.

Do you have a custom stylesheet - if so put it in there.

As you want the disabled boxes throughout your application to be the same I would put in as

input[disabled] {
   color: #444!important;
}

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It is a good idea to use important sparingly but in this case, unless there are conditions under which you want the disabled inputs to be a lighter color, you want this as a globally enforced style.
Alternative style declaration

input:disabled {
   color: #444!important;
}

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Good for inputs!

Could you please check for select?

(it doesn't run)

select select:disabled {
   color: #444!important;
}

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select select:disabled {
   color: #444!important;
}

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What you are saying here is style all disabled <select>'s that are themselves inside a <select> - which is a non existent case
Just do this

select:disabled {
   color: #444!important;
}

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I had tryed this before.  It doesn't work too.

Thank you for solution!

You are welcome.