Color Attribute Doesn't do sRGB Color Correction

## Bevy version

0.8

## Relevant system information

```
AdapterInfo { name: "NVIDIA GeForce RTX 3070 Ti", vendor: 4318, device: 9346, device_type: DiscreteGpu, backend: Vulkan }
```

## What you did

I used the `Mesh::ATTRIBUTE_COLOR` attribute to try to depict the color purple (`[1.0, 0.0, 1.0, 1.0]`) on a triangle, and it looks like this:

## What went wrong

It's showing a different color than purple, presumably because it's not applying sRGB color correction.