  In this paper, we investigate the influence of primary hair ($l$) on the
shadows of hairy Schwarzschild and Reissner-Nordstr\"om black holes obtained
through gravitational decoupling. In the context of hairy Schwarzschild black
holes, $l$ either has no effect or consistently enlarges the photon sphere
radius. Notably, even when it violates the strong energy condition, it can
decrease the radius. For Reissner-Nordstr\"om black holes, an additional matter
field consistently expands the photon sphere radius, potentially reaching $3M$,
akin to the pure Schwarzschild case. Remarkably, we demonstrate that black
holes can exist even when overcharged ($Q^2 > M^2$), casting shadows. Specific
intensity calculations reveal $l$ consistently reduces it in both scenarios.
Furthermore, we investigate the impact of pressureless plasma, finding $l$
exerts a stronger influence on visible size than plasma. These results can help
in our understanding of theoretical models of black hole shadows and can be
tested by comparison with the images obtained by EHT collaboration.
