diff --git a/petri/src/lib.rs b/petri/src/lib.rs
index fdbe655..66d85a8 100644
--- a/petri/src/lib.rs
+++ b/petri/src/lib.rs
@@ -2,11 +2,8 @@ use rand::prelude::*;
 
 pub const CHUNK_SIZE: usize = 32;
 
-#[derive(Debug, Default, PartialEq, Clone)]
-pub struct Cell(pub u8, pub u8, pub u8);
-
-#[derive(Debug)]
-pub struct Pos2(i8, i8);
+#[derive(Default, Debug, PartialEq, Clone, Copy)]
+pub struct Cell(u16);
 
 #[derive(Debug)]
 pub struct Dish {
@@ -42,7 +39,7 @@ impl Chunk {
 		for col in self.contents.iter_mut() {
 			for cell in col.iter_mut() {
 				if random::<u8>() % 4 == 0 {
-					*cell = Cell::PINK;
+					*cell = Cell(1);
 				}
 			}
 		}
@@ -62,41 +59,42 @@ impl Dish {
 	pub fn new() -> Self {
 		Self {
 			chunk: Chunk::new().fill_random(),
+
 			rules: vec![
 				Rule {
 					from: RulePattern {
 						width: 1,
 						height: 2,
-						contents: vec![Some(Cell::PINK), Some(Cell::EMPTY)],
+						contents: vec![Some(Cell(1)), Some(Cell(0))],
 					},
 					to: RulePattern {
 						width: 1,
 						height: 2,
-						contents: vec![Some(Cell::EMPTY), Some(Cell::PINK)],
+						contents: vec![Some(Cell(0)), Some(Cell(1))],
 					},
 				},
 				Rule {
 					from: RulePattern {
 						width: 2,
 						height: 2,
-						contents: vec![Some(Cell::PINK), None, Some(Cell::PINK), Some(Cell::EMPTY)],
+						contents: vec![Some(Cell(1)), None, Some(Cell(1)), Some(Cell(0))],
 					},
 					to: RulePattern {
 						width: 2,
 						height: 2,
-						contents: vec![Some(Cell::EMPTY), None, Some(Cell::PINK), Some(Cell::PINK)],
+						contents: vec![Some(Cell(0)), None, Some(Cell(1)), Some(Cell(1))],
 					},
 				},
 				Rule {
 					from: RulePattern {
 						width: 2,
 						height: 2,
-						contents: vec![None, Some(Cell::PINK), Some(Cell::EMPTY), Some(Cell::PINK)],
+						contents: vec![None, Some(Cell(1)), Some(Cell(0)), Some(Cell(1))],
 					},
 					to: RulePattern {
 						width: 2,
 						height: 2,
-						contents: vec![None, Some(Cell::EMPTY), Some(Cell::PINK), Some(Cell::PINK)],
+						contents: vec![None, Some(Cell(0)), Some(Cell(1)), Some(Cell(1))],
 					},
 				},
 			],
@@ -158,12 +156,6 @@ impl Dish {
 	}
 }
 
-impl Cell {
-	pub const EMPTY: Self = Self(0, 0, 0);
-	pub const WHITE: Self = Self(255, 255, 255);
-	pub const PINK: Self = Self(255, 147, 219);
-}
-
 #[derive(Debug)]
 pub struct RulePattern {
 	width: usize,
@@ -188,3 +180,10 @@ impl RulePattern {
 		self.width
 	}
 }
+
+impl Cell {
+	pub const EMPTY: Self = Cell(0);
+	pub fn id(&self) -> usize {
+		self.0 as usize
+	}
+}
diff --git a/uscope/src/main.rs b/uscope/src/main.rs
index ca98db5..b9c2a80 100644
--- a/uscope/src/main.rs
+++ b/uscope/src/main.rs
@@ -16,11 +16,24 @@ fn main() {
 #[derive(Debug)]
 struct UScope {
 	dish: Dish,
+	celltypes: Vec<CellData>,
+}
+
+#[derive(Default, Debug)]
+pub struct CellData {
+	name: String,
+	color: Color32,
 }
 
 impl UScope {
 	fn new(_cc: &eframe::CreationContext<'_>) -> Self {
-		Self { dish: Dish::new() }
+		Self {
+			dish: Dish::new(),
+			celltypes: vec![
+				CellData::new("air", 0, 0, 0),
+				CellData::new("pink_sand", 255, 147, 219),
+			],
+		}
 	}
 }
 
@@ -37,18 +50,18 @@ impl eframe::App for UScope {
 				dbg!(&self.dish.rules);
 			}
 			for rule in &mut self.dish.rules {
-				rule_editor(ui, rule);
+				rule_editor(ui, rule, &self.celltypes);
 			}
 		});
 		CentralPanel::default().show(ctx, |ui| {
 			let bounds = ui.available_rect_before_wrap();
 			let painter = ui.painter_at(bounds);
-			paint_chunk(painter, &self.dish.chunk);
+			paint_chunk(painter, &self.dish.chunk, &self.celltypes);
 		});
 	}
 }
 
-fn paint_chunk(painter: Painter, chunk: &Chunk) {
+fn paint_chunk(painter: Painter, chunk: &Chunk, cells: &[CellData]) {
 	let bounds = painter.clip_rect();
 	let size = 16.;
 	for x in 0..CHUNK_SIZE {
@@ -56,17 +69,18 @@ fn paint_chunk(painter: Painter, chunk: &Chunk) {
 			let cell = &chunk.get_cell(x, y);
 			let corner = bounds.min + (Vec2::from((x as f32, y as f32)) * size);
 			let rect = Rect::from_min_size(corner, Vec2::splat(size));
-			let color = Color32::from_rgb(cell.0, cell.1, cell.2);
+			let color = cells[cell.id()].color;
 			painter.rect(rect, 0., color, (1., Color32::GRAY));
 		}
 	}
 }
 
-fn rule_editor(ui: &mut Ui, rule: &mut Rule) {
+fn rule_editor(ui: &mut Ui, rule: &mut Rule, cells: &[CellData]) {
 	let patt_height = rule.from.height();
 	let patt_width = rule.from.height();
 
 	const CSIZE: f32 = 24.;
+	const OUTLINE: (f32, Color32) = (1., Color32::GRAY);
 
 	let (_, bounds) = ui.allocate_space(Vec2::new(
 		CSIZE * (patt_width * 2 + 1) as f32,
@@ -79,24 +93,24 @@ fn rule_editor(ui: &mut Ui, rule: &mut Rule) {
 				Vec2::splat(CSIZE),
 			);
 			if let Some(cell) = rule.from.get(x, y) {
-				ui.painter().rect(
-					rect,
-					2.,
-					Color32::from_rgb(cell.0, cell.1, cell.2),
-					(1., Color32::GRAY),
-				);
+				let color = cells[cell.id()].color;
+				ui.painter().rect(rect, 2., color, OUTLINE);
 			}
 
 			if let Some(cell) = rule.to.get(x, y) {
 				let rect = rect.translate(Vec2::X * (patt_width as f32 + 1.) * CSIZE);
-
-				ui.painter().rect(
-					rect,
-					2.,
-					Color32::from_rgb(cell.0, cell.1, cell.2),
-					(1., Color32::GRAY),
-				);
+				let color = cells[cell.id()].color;
+				ui.painter().rect(rect, 2., color, OUTLINE);
 			}
 		}
 	}
 }
+
+impl CellData {
+	fn new(name: &str, r: u8, g: u8, b: u8) -> Self {
+		Self {
+			name: name.to_owned(),
+			color: Color32::from_rgb(r, g, b),
+		}
+	}
+}