This study investigates how task-relevance modulates priming effects across two different visual dimensions, which are colour and shape. Participants were shown with sequentially presented coloured shapes (red/green circle/square). In the first two sessions, participants were required to react to the colour of the target while ignoring the shape; in the subsequent two sessions, participants were required to react to the shape while ignoring the colour. With the switching of relevant dimensions in the target, we examine their effect on priming. Additionally, we compared the effect of congruence between the task-relevant and task-irrelevant features. The data show clear priming effects in both tasks, color and shape. Surprisingly, only the color of the prime influenced responses on the color task, while only the shape of the prime influenced responses on the shape task. In contrast, the respective response-irrelevant feature seems to be blocked from response activation. We refer to this effect as “feature flop”, because the action triggers behave like a simple electronic flip-flop gate. Our results highlight the importance of task sets (“action trigger conditions”) for the information flow between specific stimulus features and motor responses.