Set color of TextView span in Android

Another answer would be very similar, but wouldn't need to set the text of the TextView twice

TextView TV = (TextView)findViewById(R.id.mytextview01);

Spannable wordtoSpan = new SpannableString("I know just how to whisper, And I know just how to cry,I know just where to find the answers");        

wordtoSpan.setSpan(new ForegroundColorSpan(Color.BLUE), 15, 30, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

TV.setText(wordtoSpan);

Here is a little help function. Great for when you have multiple languages!

private void setColor(TextView view, String fulltext, String subtext, int color) {
    view.setText(fulltext, TextView.BufferType.SPANNABLE);
    Spannable str = (Spannable) view.getText();
    int i = fulltext.indexOf(subtext);
    str.setSpan(new ForegroundColorSpan(color), i, i + subtext.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
}

I always find visual examples helpful when trying to understand a new concept.

Background Color

SpannableString spannableString = new SpannableString("Hello World!");
BackgroundColorSpan backgroundSpan = new BackgroundColorSpan(Color.YELLOW);
spannableString.setSpan(backgroundSpan, 0, spannableString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(spannableString);

Foreground Color

SpannableString spannableString = new SpannableString("Hello World!");
ForegroundColorSpan foregroundSpan = new ForegroundColorSpan(Color.RED);
spannableString.setSpan(foregroundSpan, 0, spannableString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(spannableString);

Combination

SpannableString spannableString = new SpannableString("Hello World!");
ForegroundColorSpan foregroundSpan = new ForegroundColorSpan(Color.RED);
BackgroundColorSpan backgroundSpan = new BackgroundColorSpan(Color.YELLOW);
spannableString.setSpan(foregroundSpan, 0, 8, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannableString.setSpan(backgroundSpan, 3, spannableString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(spannableString);

Further Study

• Explain the meaning of Span flags like SPAN_EXCLUSIVE_EXCLUSIVE
• Android Spanned, SpannedString, Spannable, SpannableString and CharSequence

If you want more control, you might want to check the TextPaint class. Here is how to use it:

final ClickableSpan clickableSpan = new ClickableSpan() {
    @Override
    public void onClick(final View textView) {
        //Your onClick code here
    }

    @Override
    public void updateDrawState(final TextPaint textPaint) {
        textPaint.setColor(yourContext.getResources().getColor(R.color.orange));
        textPaint.setUnderlineText(true);
    }
};

Set your TextView´s text spannable and define a ForegroundColorSpan for your text.

TextView textView = (TextView)findViewById(R.id.mytextview01);    
Spannable wordtoSpan = new SpannableString("I know just how to whisper, And I know just how to cry,I know just where to find the answers");          
wordtoSpan.setSpan(new ForegroundColorSpan(Color.BLUE), 15, 30, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);    
textView.setText(wordtoSpan);