Different Style for each result - php

Question

I try show all the hours of the day in order 8, 9, 10 ... but to distinguish the hours that are in the database from the hours that are not. For instance, to give a different color. Can anyone help? (I am not a programmer and I am just learning php alone, so any I would appreciate any help, but explain it in a simple way, please)
This gives me the hours that I have in the database in blue. But I cannot to get hours that are not in the database and I cannot give them another color and the right position: 8, 9,10, 11...
$result = mysqli_query($con, 'SELECT * FROM consulta
WHERE professional=1
AND client=0');
while ($row = mysqli_fetch_array($result)) {
if ($row['hour']=='09:00:00') { echo '<p style="color:blue;">9</p>'; }
elseif ($row['hour']=='10:00:00') { echo '<p style="color:blue;">10</p>'; }
elseif ($row['hour']=='11:00:00') { echo '<p style="color:blue;">11</p>'; }
elseif ($row['hour']=='12:00:00') { echo '<p style="color:blue;">12</p>'; }
}

Answer 1

Here's some sudo code for you. Make an array with all the hours in it. Then iterate that array instead of the result from the database.
for ($i = 0; $i < 24; $i++) {
if(in_array("$i:00:00", $row)) {
// hour was found in the database
echo '<p style="color:blue;">'.$i.'</p>';
} else {
// hour was not found
echo '<p style="color:red;">'.$i.'</p>';
}
}

Answer 2

This way you're iterating over hours that are in the database. Just them. So if 11 is not in the database, if simply won't show. You need a different logic.
You need to iterate over all 24 hours and for each hour check if it is in the database, if so, apply styling, if not, render normally. And a hint, it might be easier to defince CSS classes instead of using inline styling (<p class="db">9</p> instead of <p style="color:blue;">9</p>, and of course, having the db class defined properly; that way you only need to change one rule instead of styling of each element in case you want to change something).