Getting button background color in Espresso

I'm trying to get button background color with the help of this Matcher.

    public static Matcher<View> withButtonColor(int expectedColor) {

    return new BoundedMatcher<View, Button>(Button.class) {
        @Override
        public boolean matchesSafely(Button button) {
            int actualColor = 0;
            try {
                actualColor = ContextCompat.getColor(currentActivity.getBaseContext(), expectedColor);
            } catch (Exception e) {
                e.printStackTrace();
            }

            return expectedColor == actualColor;

        }

        @Override
        public void describeTo(Description description) {
            description.appendText("ERROR");
        }
    };
}

Using

onView(withId(trueButton)).check(matches(withButtonColor(ActivityPage.greenColor)));

Nothing helps though.

I pass a valid color as an argument, though actual color always equals 0 anyway. I guess there might be a problem with getting context.