svg groups and fill inheritance - svg

Question

My goal is to have the first group of 3 squares be blue and the next group of 3 squares be red. To minimize code, I want to take advantage of grouping in SVG. All the rectangles remain blue. I have tried inline styling on the second group element and on the use element, but that doesn't solve the problem. Thank you for your assistance.. Here's the code:
<svg width="1000" height="800"
xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink">
<style>
.blue {fill:blue;}
.red {fill:red;}
</style>
<g id="g1" class="blue">
<rect x="0" y="0" width="100" height="100" />
<rect x="0" y="105" width="100" height="100" />
<rect x="0" y="210" width="100" height="100" />
</g>
<g class="red">
<use xlink:href="#g1" transform="translate(0,315)" />
</g>
Here are changes from above that now have it working:
<g class="blue">
<g id="g1">
<rect x="0" y="0" width="100" height="100" />
<rect x="0" y="105" width="100" height="100" />
<rect x="0" y="210" width="100" height="100" />
</g>
</g>
<g class="red" transform="translate(0,315)">
<use xlink:href="#g1" />
<!-- <g id="g1">
<rect x="0" y="0" width="100" height="100" />
<rect x="0" y="105" width="100" height="100" />
<rect x="0" y="210" width="100" height="100" />
</g> -->
</g>
... I commented out some of the old svg as well.
Here's the solution in a clearer form (some of the commented code above, actually came from further experimenting).
<svg width="1000" height="800"
xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink">
<style>
.blue {fill:blue;}
.red {fill:red;}
</style>
<g class="blue">
<g id="g1">
<rect x="0" y="0" width="100" height="100" />
<rect x="0" y="105" width="100" height="100" />
<rect x="0" y="210" width="100" height="100" />
</g>
</g>
<g class="red" transform="translate(0,315)">
<use xlink:href="#g1" />
</g>
Looks like styling needs to be done at a level above a group in my case and that the as Robert pointed out will retrieve the previous group as written.