Multicolor mechanoluminescence (ML) materials have attracted growing attention for applications in anti‐counterfeiting, smart skin, wearable electronics, and structural health monitoring. However, their widespread implementation remains significantly hindered by the scarce available compositions and harsh preparation conditions—typically requiring temperatures above 1000°C and protective atmospheres. Here, a facile, low‐temperature, and atmosphere‐free synthesis of calcium borate‐based ML materials (Ca₂B₂O₅ and CaB₂O₄) is achieved. The phase ratio of Ca₂B₂O₅ and CaB₂O₄ is manipulated by adjusting the stoichiometric ratio of raw materials (H₃BO₃ and CaO). The distinct tetrahedral and octahedral coordination of Mn²⁺ in these phases gives rise to tunable ML emission spanning from green to orange (535–605 nm). When incorporated into polydimethylsiloxane (PDMS) elastomers, these …