Since it is not easy to customize the color of the error in a TextInputLayout, I decided to change my error colour to match the one used by default by TextInputLayout.
In the design guidelines I could not find the definition of the default colour.
Do you know where I can find it?
Update in 2020.
TextInputLayout error color can be acquired via:
ContextCompat.getColor(this, com.google.android.material.R.color.design_error)
But it is marked private and can be changed. Approximately color value is:
<color name="color_text_input_error_color">#E87850</color>