Change color font only in part of textview

Change color font only in part of textview

i want to change only a part of textview color.. I've tried in this way
but nothing change
TextView textView = (TextView)findViewById(R.id.Temperature);
textView.setText("Temperature: "+ "<small> <font color='#59c3fa'>" +
temperature + "°C</font></small>");
So the first part "Temperature: " has to have the textview color (Black in
this case), and the rest of part with this #59c3fa. How is wrong?