Rapid eye movement (REM) sleep is associated with dreaming and emotional processing, yet how dream emotional content is reflected in EEG spectral patterns remains unclear. In this study, EEG spectral features during REM sleep were analyzed to examine whether negative, neutral, and positive dream emotions can be differentiated based on electrophysiological activity. To align EEG recordings with dream reports, the final three minutes of each REM segment before awakening were extracted from DEED. Spectral features were computed from six electrodes: F3, F4, FT7, FT8, T7, and T8. For each electrode, absolute power, relative power, and inter-band power ratios were calculated across delta, theta, alpha, beta, and gamma frequency bands, resulting in 120 EEG features per sample. Differences among the three dream-emotion groups were assessed using one-way analysis of covariance, with REM cycle number as a covariate. Bonferroni and false discovery rate corrections were applied for multiple comparisons, and pairwise comparisons were performed using Welch’s t-test on REM-adjusted values. After Bonferroni correction, 11 EEG spectral features remained significant. These features were located over temporal, fronto-temporal, and frontal electrodes and related to alpha-band indices and delta/alpha ratios. Post-hoc analyses identified 15 significant pairwise differences after FDR correction, with most prominent differences between positive and neutral dreams. Compared with neutral dreams, positive dreams showed lower alpha-related indices and alpha-centered ratios over temporal regions, together with higher frontal delta/alpha ratios. In contrast, negative dreams differed from neutral dreams only in relative delta power at FT7. These findings suggest that REM dream emotion is associated with measurable but subtle EEG spectral changes. The dominant pattern involved reduced temporal alpha-related activity and increased frontal delta/alpha ratios in positive dreams relative to neutral dreams.