Index: binaries/data/mods/public/gui/session/unit_actions.js
===================================================================
--- binaries/data/mods/public/gui/session/unit_actions.js
+++ binaries/data/mods/public/gui/session/unit_actions.js
@@ -578,13 +578,13 @@
 				break;
 
 			case "set second":
-				if (tradingDetails.gain.traderGain == 0) // markets too close
-					return false;
-
-				tooltip = translate("Right-click to set as destination trade market.") + "\n" +
-					sprintf(translate("Gain: %(gain)s"), {
-						"gain": getTradingTooltip(tradingDetails.gain)
-					});
+				if (tradingDetails.gain.traderGain == 0)
+					tooltip = translate(setStringTags("Market is too close to first one.", { "color": "255 0 0" }) + "\nRight-click to cancel.");
+				else
+					tooltip = translate("Right-click to set as destination trade market.") + "\n" +
+						sprintf(translate("Gain: %(gain)s"), {
+							"gain": getTradingTooltip(tradingDetails.gain)
+						});
 
 				break;
 			}