diff --git a/reco/royfit.jl b/reco/royfit.jl
index fe3cc95249c7b46262ce7543bac023137fd4136a..442fbc13b180d7003e4533ff54262c84a88e79cf 100644
--- a/reco/royfit.jl
+++ b/reco/royfit.jl
@@ -58,7 +58,7 @@ function main()
             end
             fit = NeRCA.single_du_fit(du_hits, sparams)
             push!(Q, fit.Q)
-            plot!(du_hits, fit, markercolor=colours[idx], label="DU $(du)", max_z=calib.max_z)
+            plot!(du_hits, fit, markercolor=colours[idx % length(colours)], label="DU $(du)", max_z=calib.max_z)
             write_time_residuals("/data/reco_timeres.csv", event, fit.selected_hits, fit)
         end
         if sum(Q) < 200 && n_doms > 6 && n_dus > 1