在开始和居中的行中排列元素

I have a dilemma that I can't seem to solve. I have an existing row in Flutter. Essentially what I want to accomplish is to have the first element(yellow) at the start of the row, and the second element(red) in the center of the element. I know Row has the mainAxisAlignment, but I need a different alignment for each each element (i.e. both MainAxisAlignment.start & MainAxisAlignment.center). Thanks for any help!

我能够得出的最接近的结果是：

Row(
      mainAxisAlignment: MainAxisAlignment.start,
      children: <Widget>[
        yellowElement,
        Expanded(child: redElement),
      ],
    );

但这并不是完全居中，而是在黄色占据其空间后剩余的可用空间中居中。