diff --git a/app-proto/sketch-outline/main.css b/app-proto/sketch-outline/main.css
index 9e8cdb4..cd7bc44 100644
--- a/app-proto/sketch-outline/main.css
+++ b/app-proto/sketch-outline/main.css
@@ -26,7 +26,7 @@ li {
   border-radius: 8px;
 }
 
-li:focus {
+li.selected {
   color: #fff;
   background-color: #666;
 }
@@ -52,7 +52,7 @@ li > .elt-rep > div {
   background-color: #333;
 }
 
-li:focus > .elt-rep > div {
+li.selected > .elt-rep > div {
   background-color: #555;
 }
 
diff --git a/app-proto/sketch-outline/src/assembly.rs b/app-proto/sketch-outline/src/assembly.rs
index b53e38d..dded2a1 100644
--- a/app-proto/sketch-outline/src/assembly.rs
+++ b/app-proto/sketch-outline/src/assembly.rs
@@ -7,6 +7,10 @@ pub struct Element {
     pub label: String,
     pub color: [f32; 3],
     pub rep: DVector<f64>,
+    
+    /* TO DO */
+    // does this belong in the element data?
+    pub selected: Signal<bool>
 }
 
 // a complete, view-independent description of an assembly
diff --git a/app-proto/sketch-outline/src/display.rs b/app-proto/sketch-outline/src/display.rs
index f3804f6..70beacf 100644
--- a/app-proto/sketch-outline/src/display.rs
+++ b/app-proto/sketch-outline/src/display.rs
@@ -101,6 +101,11 @@ pub fn Display() -> View {
     
     // change listener
     let scene_changed = create_signal(true);
+    create_effect(move || {
+        let elements = state.assembly.elements.get_clone();
+        for elt in elements { elt.selected.track(); }
+        scene_changed.set(true);
+    });
     
     /* INSTRUMENTS */
     const SAMPLE_PERIOD: i32 = 60;
@@ -284,7 +289,13 @@ pub fn Display() -> View {
                 let elements = state.assembly.elements.get_clone();
                 let element_iter = (&elements).into_iter();
                 let reps_world: Vec<_> = element_iter.clone().map(|elt| &assembly_to_world * &elt.rep).collect();
-                let colors: Vec<_> = element_iter.map(|elt| elt.color).collect();
+                let colors: Vec<_> = element_iter.map(|elt|
+                    if elt.selected.get() {
+                        elt.color.map(|ch| 0.5 + 0.5*ch)
+                    } else {
+                        elt.color
+                    }
+                ).collect();
                 
                 // set the resolution
                 let width = canvas.width() as f32;
diff --git a/app-proto/sketch-outline/src/main.rs b/app-proto/sketch-outline/src/main.rs
index ee7682a..06cc43d 100644
--- a/app-proto/sketch-outline/src/main.rs
+++ b/app-proto/sketch-outline/src/main.rs
@@ -24,19 +24,22 @@ fn main() {
                             id: String::from("wing_a"),
                             label: String::from("Wing A"),
                             color: [1.00_f32, 0.25_f32, 0.00_f32],
-                            rep: DVector::<f64>::from_column_slice(&[0.5, 0.5, 0.0, 0.5, -0.25])
+                            rep: DVector::<f64>::from_column_slice(&[0.5, 0.5, 0.0, 0.5, -0.25]),
+                            selected: create_signal(false)
                         },
                         Element {
                             id: String::from("wing_b"),
                             label: String::from("Wing B"),
                             color: [0.00_f32, 0.25_f32, 1.00_f32],
-                            rep: DVector::<f64>::from_column_slice(&[-0.5, -0.5, 0.0, 0.5, -0.25])
+                            rep: DVector::<f64>::from_column_slice(&[-0.5, -0.5, 0.0, 0.5, -0.25]),
+                            selected: create_signal(false)
                         },
                         Element {
                             id: String::from("central"),
                             label: String::from("Central"),
                             color: [0.75_f32, 0.75_f32, 0.75_f32],
-                            rep: DVector::<f64>::from_column_slice(&[0.0, 0.0, 0.0, 0.4, -0.625])
+                            rep: DVector::<f64>::from_column_slice(&[0.0, 0.0, 0.0, 0.4, -0.625]),
+                            selected: create_signal(false)
                         }
                     ])
                 }
diff --git a/app-proto/sketch-outline/src/outline.rs b/app-proto/sketch-outline/src/outline.rs
index 546b272..5d650b3 100644
--- a/app-proto/sketch-outline/src/outline.rs
+++ b/app-proto/sketch-outline/src/outline.rs
@@ -1,5 +1,6 @@
 use itertools::Itertools;
 use sycamore::{prelude::*, web::tags::div};
+use web_sys::KeyboardEvent;
 
 use crate::AppState;
 
@@ -21,6 +22,9 @@ pub fn Outline() -> View {
             Keyed(
                 list=elements_sorted,
                 view=|elt| {
+                    let class = create_memo(move ||
+                        if elt.selected.get() { "selected" } else { "" }
+                    );
                     let label = elt.label.clone();
                     let rep_components = elt.rep.iter().map(|u| {
                         let u_coord = u.to_string().replace("-", "\u{2212}");
@@ -29,7 +33,19 @@ pub fn Outline() -> View {
                     view! {
                         /* [TO DO] switch to integer-valued parameters whenever
                         that becomes possible again */
-                        li(tabindex="0") {
+                        li(
+                            class=class.get(),
+                            tabindex="0",
+                            on:click=move |_| {
+                                elt.selected.set_fn(|sel| !sel);
+                            },
+                            on:keydown=move |event: KeyboardEvent| {
+                                if event.key() == "Enter" {
+                                    elt.selected.set_fn(|sel| !sel);
+                                    event.prevent_default();
+                                }
+                            }
+                        ) {
                             div(class="elt-label") { (label) }
                             div(class="elt-rep") { (rep_components) }
                         }