The function "calcBlendColor" in the file texteditor.cpp return same color.

    if (level == count)
        return baseColor;
    if (level == 0)
        return color80;
    if (level == count - 1)
        return color90;

    const int blendFactor = level * (256 / (count - 2));

    return blendColors(color80, color90, blendFactor);