diff --git a/core/assets-raw/sprites/units/omura-cannon-heat.png b/core/assets-raw/sprites/units/omura-cannon-heat.png
new file mode 100644
index 0000000000..e7dd256003
Binary files /dev/null and b/core/assets-raw/sprites/units/omura-cannon-heat.png differ
diff --git a/core/assets-raw/sprites/units/omura-cannon.png b/core/assets-raw/sprites/units/omura-cannon.png
new file mode 100644
index 0000000000..1a21b9acd8
Binary files /dev/null and b/core/assets-raw/sprites/units/omura-cannon.png differ
diff --git a/core/src/mindustry/ui/dialogs/ResearchDialog.java b/core/src/mindustry/ui/dialogs/ResearchDialog.java
index d2bd13c101..d7540d2764 100644
--- a/core/src/mindustry/ui/dialogs/ResearchDialog.java
+++ b/core/src/mindustry/ui/dialogs/ResearchDialog.java
@@ -340,7 +340,7 @@ public class ResearchDialog extends BaseDialog{
                 button.update(() -> {
                     float offset = (Core.graphics.getHeight() % 2) / 2f;
                     button.setPosition(node.x + panX + width / 2f, node.y + panY + height / 2f + offset, Align.center);
-                    button.getStyle().up = !locked(node.node) ? Tex.buttonOver : selectable(node.node) && !canSpend(node.node) ? Tex.buttonRed : Tex.button;
+                    button.getStyle().up = !locked(node.node) ? Tex.buttonOver : !selectable(node.node) || !canSpend(node.node) ? Tex.buttonRed : Tex.button;
 
                     ((TextureRegionDrawable)button.getStyle().imageUp).setRegion(node.selectable ? node.node.content.icon(Cicon.medium) : Icon.lock.getRegion());
                     button.getImage().setColor(!locked(node.node) ? Color.white : node.selectable ? Color.gray : Pal.gray);