How can I save colors in 'array.xml' and get it back to a Color[] array?

Define your color resources, then add them to an array for access.

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="bright_pink">#FF007F</color>
    <color name="red">#FF0000</color>
    <color name="orange">#FF7F00</color>
    <color name="yellow">#FFFF00</color>
    <color name="chartreuse">#7FFF00</color>
    <color name="green">#00FF00</color>
    <color name="spring_green">#00FF7F</color>
    <color name="cyan">#00FFFF</color>
    <color name="azure">#007FFF</color>
    <color name="blue">#0000FF</color>
    <color name="violet">#7F00FF</color>
    <color name="magenta">#FF00FF</color>

    <array name="rainbow">
        <item>@color/bright_pink</item>
        <item>@color/red</item>
        <item>@color/orange</item>
        <item>@color/yellow</item>
        <item>@color/chartreuse</item>
        <item>@color/green</item>
        <item>@color/spring_green</item>
        <item>@color/cyan</item>
        <item>@color/azure</item>
        <item>@color/blue</item>
        <item>@color/violet</item>
        <item>@color/magenta</item>
    </array>
</resources>

Then access them like this:

int[] rainbow = context.getResources().getIntArray(R.array.rainbow);

for (int i = 0; i < tileColumns; i++) {
    paint.setColor(rainbow[i]);
    // Do something with the paint.
}

If this is in array.xml:

<resources>
    <array name="colors">
        <item>#ffffff</item>
        <item>#000000</item>
    </array>
</resources>

This will give you the color values for that array:

TypedArray ta = context.getResources().obtainTypedArray(R.array.colors);
int[] colors = new int[ta.length()];
for (int i = 0; i < ta.length(); i++) {
    colors[i] = ta.getColor(i, 0);
}
ta.recycle();

This just expands on the TypedArray example in the documentation: Typed array

colors.xml

<resources>
    <string-array name="colors">        
        <item>#ff0000</item>
        <item>#00ff00</item>  
        <item>#0000ff</item>
    </string-array>
</resources>

Code in activity class.

String[] allColors = context.getResources().getStringArray(R.array.colors);

Color.parseColor(allColors[0]) // red
Color.parseColor(allColors[1]) // green
Color.parseColor(allColors[2]) // blue

I can't post a comment, so I must put this in as a new response. I completely agree with Sky Kelsey w.r.t. design choice of using color resource type. However, I found the suggest method to access them did not work. This is the way I implemented the use of an XML array to easily loop through a list of colors and apply the colors to various (Custom painted) views.

First the array in arrays.xml:

    <array name="ingr_color_arr">
      <item>@color/ingr_red1</item>
      <item>@color/ingr_orange1</item>
      <item>@color/ingr_yellow1</item>
      <item>@color/ingr_green1</item>
      <item>@color/ingr_blue1</item>
      <item>@color/ingr_violet1</item>
      <item>@color/ingr_red2</item>
      <item>@color/ingr_orange2</item>
      <item>@color/ingr_yellow2</item>
      <item>@color/ingr_green2</item>
      <item>@color/ingr_blue2</item>
      <item>@color/ingr_violet2</item>
   </array>

Then in color.xml:

<color name="ingr_red1">#FFCC0000</color>
<color name="ingr_orange1">#FFED5F21</color>
<color name="ingr_yellow1">#FFFAE300</color>
<color name="ingr_green1">#FF5B9C0A</color>
<color name="ingr_blue1">#FF0A0D9C</color>
<color name="ingr_violet1">#FF990A9C</color>
<color name="ingr_red2">#FFFFCCCC</color>
<color name="ingr_orange2">#FFFFEACC</color>
<color name="ingr_yellow2">#FFFFFECC</color>
<color name="ingr_green2">#FFC7F5C4</color>
<color name="ingr_blue2">#FFC4DAF4</color>
<color name="ingr_violet2">#FFE1C4F4</color>

Then to use it:

TypedArray ta = res.obtainTypedArray(R.array.ingr_color_arr);
int colorToUse = ta.getResourceId(intGroupNum.intValue() - 1, R.color.recipe_detail_border);
paint.setColor(colorToUse);

The key here is to use getResourceId because setColor(int) is going to expect a resource id for a color. I was getting "Resource not found" errors when I tried getting the value with getIntArray() or getColor().

The most popular answer may work...I didn't try it because I preferred the 'array of colors' design choice better.

In Kotlin that will be much simpler

 val colors = resources.obtainTypedArray(R.array.colors).use { ta ->
     IntArray(ta.length()) { ta.getColor(it, 0) }
 }

If you use integer-array, you can directly grab the color:

File colors.xml

<color name="easy">#FF0000</color>
<color name="normal">#00FF00</color>
<color name="hard">#0000FF</color>

<integer-array name="colors_difficulty">
    <item>@color/easy</item>
    <item>@color/normal</item>
    <item>@color/hard</item>
</integer-array>

Code

val colorsDif = resources.getIntArray(R.array.colors_dificulty);
view.setBackgroundColor(colorsDif[0])

Color.xml:

 <string-array name="listcolors">
        <item>#448AFF</item>
        <item>#FFC107</item>
        <item>#009688</item>
        <item>#ff8000</item>
        <item>#ffbf00</item>
        <item>#0000ff</item>
        <item>#936c6c</item>
        <item>#7733ff</item>
        <item>#7733ff</item>
        <item>#ff8000</item>
        <item>#448AFF</item>
        <item>#0000ff</item>
    </string-array>

activity.java file

Context context;
 String[] colors = context.getResources().getStringArray(R.array.listcolors);

 String bg_color = colors[i]; //i=1,2,3...

<color name="gblue">#4285F4</color>
<color name="ggreen">#34A853</color>
<color name="gyellow">#FBBC05</color>
<color name="gred">#EA4335</color>

<array name="google_colors">
    <item>@color/gblue</item>
    <item>@color/ggreen</item>
    <item>@color/gyellow</item>
    <item>@color/gred</item>
</array>

Use this in Java, Kotlin, or style. Do not use in XML.

You can also have a nice Kotlin extension function:

fun Resources.getColorsArray(@ArrayRes arrayResId: Int): IntArray {
    obtainTypedArray(arrayResId).use { typedArray ->
        val length = typedArray.length()
        val colors = IntArray(length)
        for (i in 0 until length)
            colors[i] = typedArray.getColor(i, 0)
        return colors
    }
}

Usage:

    <array name="presets_colors">
        <item>#FF0000ff</item>
        <item>#FF00ff00</item>
        <item>#FF00ffff</item>
        <item>#FFff0000</item>
        <item>#FFff00ff</item>
        <item>#FFffff00</item>
    </array>

val presetsColors = resources.getColorsArray(R.array.presets_colors)