<p>Successful memory performance requires maintaining target representations while resisting distractor interference. Although prior event-related potential (ERP) studies linked cognitive resources to distractor resistance by controlling stimulus similarity, how other visual representational properties modulate this resistance remain unclear. Here, we employed ERPs to investigate visual working memory resistance mechanisms during maintenance by manipulating <i>color-semantic congruency</i>, with focus on alpha-band suppression. Distractor presentation elicited enhanced N2 amplitudes and alpha desynchronization. Crucially, color-semantically congruent conditions during maintenance showed stronger alpha synchronization than non-distractor conditions. These findings indicate that initial alpha activity reflects active distractor processing (potentially due to low target perceptual load), while heightened resistance under congruency is mediated by alpha synchronization and likely tied to available cognitive resources. Public Significance Statement. People often need to keep visual information in mind while ignoring distractions, such as when driving or studying. We show that when an object’s typical color matches its meaning (e.g., a yellow banana), visual working memory is more resistant to irrelevant color distractors, and this protection is reflected in stronger alpha‑band activity after distraction. These findings identify a brain marker of distractor resistance and suggest routes to reduce distraction in everyday tasks.</p>