How can I change the action bar search view hint text colour?
This question explains how to get the EditText when using ABS: Android ActionBar Customize Search View
Try this code. It is very easy.
// Associate searchable configuration with the SearchView
SearchManager searchManager =
(SearchManager) getSystemService(Context.SEARCH_SERVICE);
SearchView searchView =
(SearchView) menu.findItem(R.id.search).getActionView();
EditText searchEditText = (EditText) searchView.findViewById(android.support.v7.appcompat.R.id.search_src_text);
searchEditText.setHint("Search");
searchEditText.setHintTextColor(getResources().getColor(R.color.white));
searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
searchEditText.setHintTextColor(getResources().getColor(R.color.white));