Fix a couple things that bother me

src/control.lua

@@ -89,18 +89,14 @@ script.on_configuration_changed(
 )
 
 script.on_event(
-    {
-        defines.events.on_script_trigger_effect
-    },
+    defines.events.on_script_trigger_effect,
     function (event)
         labRenderers.addLab(event.target_entity)
     end
 )
 
 script.on_event(
-    {
-        defines.events.on_object_destroyed
-    },
+    defines.events.on_object_destroyed,
     function (event)
         if event.type ~= defines.target_type.entity then return end
         labRenderers.removeLab(event.useful_id)
@@ -116,7 +112,7 @@ script.on_nth_tick(
 )
 
 script.on_event(
-    {defines.events.on_tick},
+    defines.events.on_tick,
     function (event)
         researchColor.validateIngredientColors()
         labColoring.updateRenderers(event, labRenderers, researchColor)

src/core/labRenderers.lua

@@ -36,7 +36,7 @@ labRenderers.createAnimation = function (entity)
         x_scale = scale,
         y_scale = scale,
         render_layer = "higher-object-under",
-        animation_offset = floor(random()*300),
+        animation_offset = random(300)-1, -- `random()` is [0,1), but `random(m)` is [1,m]
         visible = false,
     })
 end
@@ -50,18 +50,18 @@ labRenderers.isCompatibleLab = function (entity)
 end
 
 labRenderers.addLab = function (entity)
-    if not entity or not entity.valid then
+    if not entity or not entity.valid
+    or not labRenderers.isCompatibleLab(entity) then
         return
     end
-    if labRenderers.isCompatibleLab(entity) then
-        local labUnitNumber = entity.unit_number
-        if labRenderers.state.labs[labUnitNumber] then
-            return
-        end
-        labRenderers.state.labs[labUnitNumber] = entity
-        if not labRenderers.state.labAnimations[labUnitNumber] then
-            labRenderers.createAnimation(entity)
-        end
+
+    local labUnitNumber = entity.unit_number
+    if labRenderers.state.labs[labUnitNumber] then
+        return
+    end
+    labRenderers.state.labs[labUnitNumber] = entity
+    if not labRenderers.state.labAnimations[labUnitNumber] then
+        labRenderers.createAnimation(entity)
     end
     script.register_on_object_destroyed(entity)
 end
@@ -70,8 +70,7 @@ labRenderers.reloadLabs = function ()
     labRenderers.state.labs = {}
     labRenderers.state.labAnimations = {}
     rendering.clear("DiscoScience")
-    for surfaceIndex in pairs(game.surfaces) do
-        local surface = game.get_surface(surfaceIndex)
+    for _, surface in pairs(game.surfaces) do
         for index, lab in ipairs(surface.find_entities_filtered({type = "lab"})) do
             labRenderers.addLab(lab)
         end

src/core/researchColor.lua

@@ -8,8 +8,6 @@ researchColor.defaultColors = { {r = 1.0, g = 0.0, b = 1.0} }
 
 researchColor.state = {}
 
-researchColor.validated = false
-
 researchColor.linkState = function (state)
     researchColor.state = state
     return state
@@ -49,16 +47,11 @@ researchColor.validateIngredientColors = function()
         return
     end
     researchColor.state.validated = true
-    local techPrototypes = prototypes.get_technology_filtered({})
+    local techPrototypes = prototypes.technology
     local notFound = {}
     for _, tech in pairs(techPrototypes) do
         for _, ingredient in pairs(tech.research_unit_ingredients) do
-            local found = false
-            for name, _ in pairs(researchColor.state.ingredientColors) do
-                if name == ingredient.name then
-                    found = true
-                end
-            end
+            local found = researchColor.state.ingredientColors[ingredient.name] and true or false
             if not (found or notFound[ingredient.name]) then
                 notFound[ingredient.name] = true
             end
@@ -76,14 +69,15 @@ end
 
 
 researchColor.assembleColorsForResearch = function (tech)
-    local colors = {}
+    local colors, colorCount = {}, 0
     for index, ingredient in pairs(tech.research_unit_ingredients) do
         local ingredientColor = researchColor.state.ingredientColors[ingredient.name]
         if ingredientColor then
-            colors[#colors + 1] = ingredientColor
+            colorCount = colorCount + 1
+            colors[colorCount] = ingredientColor
         end
     end
-    if #colors == 0 then
+    if colorCount == 0 then
         colors = researchColor.defaultColors
     end
     return colors