diff --git a/okolors/src/kmeans.rs b/okolors/src/kmeans.rs
index e12b10d..9a34a32 100644
--- a/okolors/src/kmeans.rs
+++ b/okolors/src/kmeans.rs
@@ -158,7 +158,7 @@ fn kmeans_plus_plus<D: ColorDifference>(
 			*weight = f32::min(*weight, D::squared_distance(color, centroid));
 		}
 
-		match WeightedIndex::new(weights.iter().copied()) {
+		match WeightedIndex::new(&*weights) {
 			Ok(sampler) => centroids.push(colors[sampler.sample(rng)]),
 			Err(AllWeightsZero) => return, // all points exactly match a centroid
 			Err(InvalidWeight | NoItem | TooMany) => {
diff --git a/okolors/src/lib.rs b/okolors/src/lib.rs
index 8ef53b8..122c0fb 100644
--- a/okolors/src/lib.rs
+++ b/okolors/src/lib.rs
@@ -431,7 +431,7 @@ mod tests {
 
 	fn test_colors() -> Vec<Srgb<u8>> {
 		let range = (0..u8::MAX).step_by(16);
-		let mut colors = Vec::new();
+		let mut colors = Vec::with_capacity(range.len().pow(3));
 
 		for r in range.clone() {
 			for g in range.clone() {