When selecting the colors for your text in the design section of the app you should consider the inheritance model so that you can rely on text or block style settings without having to make too many different text styles just for color.
First, Default Colors.
The color for the text is determined by the "Default Colors" setting for text. All text will use the default text color by default.
Second, Text Style Color.
If a color is set for the text style in the typography section of the design area of the app this will be the only color for the text. If you would prefer to rely on the block text color then you should leave the text color as blank/none in this section.
Third, Block Text Color
The text will use the selected block style text color only if there is no color set in the chosen text style's text color setting.