Why can't I set app:helperTextTextColor="@color/red"?

Question

I'm currently watching a tutorial on how to create the "Required*" helper text on a textInputLayout. In the video he is able to set the text color to red using the code below, but when i try to do it, the only colors available are black, teal, white and purple.

in activity_main.xml:

<com.google.android.material.textfield.TextInputLayout 
...
app:helperText="Required*"
app:helperTextTextColor="@color/red"
...
>

sorry if the format of my question is wonky, this is my first ever post.

Answer 1

@color/ refers to a named color in the colors.xml resource In app / res / values you may have a file colors.xml You may only have the 4 entries you mention defined.

Example contents:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="black">#FF000000</color>
    <color name="white">#FFFFFFFF</color>
    <color name="yellow">#FFFF00</color>
    <color name="fuchsia">#FF00FF</color>
    <color name="red">#FF0000</color>
    <color name="silver">#C0C0C0</color>
    <color name="gray">#808080</color>
    <color name="olive">#808000</color>
</resources>