PHP diff array value and not key diff

I have a problem and i hope i can be helped to fix this problem.

my problem is i got this two arrays

$array1 = ["test1" => "red", "test2" => "blue", "test3" => "green"];
$array2 = ["test1" => "red", "test2" => "blue", "test3" => "blue"];

as you can see the diffiend is the array key test3's value there are a diff, my problem is i need to know the key test3 have a diff and from $array1 to $array2

i have tryed array_diff and array_intersect but its not what i want, i have a product and i need to know what there are changes from last run, and if i use on of this to command its not telling my where the diff are but what the diff is.

can sombardy help here and explain what i can do or about there are a function to handle this problem?