Add optional color component to BarChart archetype (#4372)

### What
- Resolves: #1355

```
"""Create and log a bar chart."""

import rerun as rr

rr.init("rerun_example_bar_chart", spawn=True)
rr.log("bar_chart", rr.BarChart([8, 4, 0, 9, 1, 4, 1, 6, 9, 0], color=(255, 0, 0)))
```


![image](https://github.com/rerun-io/rerun/assets/3312232/6af1ad96-0683-401c-ac82-3f7cf0ade57d)


### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested [app.rerun.io](https://app.rerun.io/pr/4372) (if
applicable)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG

- [PR Build Summary](https://build.rerun.io/pr/4372)
- [Docs
preview](https://rerun.io/preview/44d44da7cf0e5ce66a48273fdcd24695bf965331/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/44d44da7cf0e5ce66a48273fdcd24695bf965331/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

crates/re_space_view_bar_chart/src/space_view_class.rs

@@ -164,8 +164,10 @@ impl SpaceViewClass for BarChartSpaceView {
                 fn create_bar_chart<N: Into<f64>>(
                     ent_path: &EntityPath,
                     values: impl Iterator<Item = N>,
+                    color: &Option<re_types::components::Color>,
                 ) -> BarChart {
-                    let color = auto_color(hash(ent_path) as _);
+                    let color =
+                        color.map_or_else(|| auto_color(hash(ent_path) as _), |color| color.into());
                     let fill = color.gamma_multiply(0.75).additive(); // make sure overlapping bars are obvious
                     BarChart::new(
                         values
@@ -183,25 +185,45 @@ impl SpaceViewClass for BarChartSpaceView {
                     .color(color)
                 }
 
-                for (ent_path, tensor) in charts {
+                for (ent_path, (tensor, color)) in charts {
                     let chart = match &tensor.buffer {
-                        TensorBuffer::U8(data) => create_bar_chart(ent_path, data.iter().copied()),
-                        TensorBuffer::U16(data) => create_bar_chart(ent_path, data.iter().copied()),
-                        TensorBuffer::U32(data) => create_bar_chart(ent_path, data.iter().copied()),
-                        TensorBuffer::U64(data) => {
-                            create_bar_chart(ent_path, data.iter().copied().map(|v| v as f64))
+                        TensorBuffer::U8(data) => {
+                            create_bar_chart(ent_path, data.iter().copied(), color)
                         }
-                        TensorBuffer::I8(data) => create_bar_chart(ent_path, data.iter().copied()),
-                        TensorBuffer::I16(data) => create_bar_chart(ent_path, data.iter().copied()),
-                        TensorBuffer::I32(data) => create_bar_chart(ent_path, data.iter().copied()),
-                        TensorBuffer::I64(data) => {
-                            create_bar_chart(ent_path, data.iter().copied().map(|v| v as f64))
+                        TensorBuffer::U16(data) => {
+                            create_bar_chart(ent_path, data.iter().copied(), color)
                         }
+                        TensorBuffer::U32(data) => {
+                            create_bar_chart(ent_path, data.iter().copied(), color)
+                        }
+                        TensorBuffer::U64(data) => create_bar_chart(
+                            ent_path,
+                            data.iter().copied().map(|v| v as f64),
+                            color,
+                        ),
+                        TensorBuffer::I8(data) => {
+                            create_bar_chart(ent_path, data.iter().copied(), color)
+                        }
+                        TensorBuffer::I16(data) => {
+                            create_bar_chart(ent_path, data.iter().copied(), color)
+                        }
+                        TensorBuffer::I32(data) => {
+                            create_bar_chart(ent_path, data.iter().copied(), color)
+                        }
+                        TensorBuffer::I64(data) => create_bar_chart(
+                            ent_path,
+                            data.iter().copied().map(|v| v as f64),
+                            color,
+                        ),
                         TensorBuffer::F16(data) => {
-                            create_bar_chart(ent_path, data.iter().map(|f| f.to_f32()))
+                            create_bar_chart(ent_path, data.iter().map(|f| f.to_f32()), color)
+                        }
+                        TensorBuffer::F32(data) => {
+                            create_bar_chart(ent_path, data.iter().copied(), color)
+                        }
+                        TensorBuffer::F64(data) => {
+                            create_bar_chart(ent_path, data.iter().copied(), color)
                         }
-                        TensorBuffer::F32(data) => create_bar_chart(ent_path, data.iter().copied()),
-                        TensorBuffer::F64(data) => create_bar_chart(ent_path, data.iter().copied()),
                         TensorBuffer::Jpeg(_) => {
                             re_log::warn_once!(
                                 "trying to display JPEG data as a bar chart ({:?})",

crates/re_space_view_bar_chart/src/view_part_system.rs

@@ -4,6 +4,7 @@ use re_arrow_store::LatestAtQuery;
 use re_data_store::EntityPath;
 use re_types::{
     archetypes::{BarChart, Tensor},
+    components::Color,
     datatypes::TensorData,
     Archetype, ComponentNameSet,
 };
@@ -15,7 +16,7 @@ use re_viewer_context::{
 /// A bar chart system, with everything needed to render it.
 #[derive(Default)]
 pub struct BarChartViewPartSystem {
-    pub charts: BTreeMap<EntityPath, TensorData>,
+    pub charts: BTreeMap<EntityPath, (TensorData, Option<Color>)>,
 }
 
 impl NamedViewSystem for BarChartViewPartSystem {
@@ -82,10 +83,17 @@ impl ViewPartSystem for BarChartViewPartSystem {
                 &query,
             );
 
+            let color = store.query_latest_component::<re_types::components::Color>(
+                &data_result.entity_path,
+                &query,
+            );
+
             if let Some(tensor) = tensor {
                 if tensor.is_vector() {
-                    self.charts
-                        .insert(data_result.entity_path.clone(), tensor.value.0.clone());
+                    self.charts.insert(
+                        data_result.entity_path.clone(),
+                        (tensor.value.0.clone(), color.map(|c| c.value)),
+                    );
                     // shallow clones
                 }
             }

crates/re_types/definitions/rerun/archetypes/bar_chart.fbs

@@ -18,4 +18,9 @@ table BarChart (
 
   /// The values. Should always be a rank-1 tensor.
   values: rerun.components.TensorData ("attr.rerun.component_required", required, order: 1000);
+
+  // --- Optional ---
+
+  /// The color of the bar chart
+  color: rerun.components.Color ("attr.rerun.component_optional", nullable, order: 2000);
 }