Change text color of one word in a TextView

t.setText(first + next, BufferType.SPANNABLE);
Spannable s = (Spannable)t.getText();
int start = first.length();
int end = start + next.length();
s.setSpan(new ForegroundColorSpan(0xFFFF0000), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

you have to use spannable this will also allows you to increase some text's size, make it bold etc.... even put in some image.

Use SpannableStringBuilder like this :

SpannableStringBuilder builder = new SpannableStringBuilder();

SpannableString str1= new SpannableString("Text1");
str1.setSpan(new ForegroundColorSpan(Color.RED), 0, str1.length(), 0);
builder.append(str1);

SpannableString str2= new SpannableString(appMode.toString());
str2.setSpan(new ForegroundColorSpan(Color.GREEN), 0, str2.length(), 0);
builder.append(str2);

TextView tv = (TextView) view.findViewById(android.R.id.text1);
tv.setText( builder, TextView.BufferType.SPANNABLE);

for long string you can use this:

String help = getString(R.string.help);
help = help.replace("some word", "<font color='#EE0000'>some word</font>");
txtDesc.setText(Html.fromHtml(help));

Easiest way I know is to just use html.

String first = "This word is ";
String next = "<font color='#EE0000'>red</font>";
t.setText(Html.fromHtml(first + next));

But this will require you to rebuild the TextView when (if?) you want to change the color, which could cause a hassle.