what's the difference traffic sign on blue sky

difference traffic sign blue sky 's difference distinction contrast divergence disparity variation dissimilarity discrepancy unlikeness inequality dissimilitude dissemblance disagreement contradiction differentiation distinctiveness diversity heterogeneity variance contrasting factors distinguishing features unique characteristics varied elements aspects dissimilarities discrepant points distinct contrasts notable disparities clear differences key discrepancies defining evident variations salient distinctions marked noteworthy prominent obvious major divergences disagreements core fundamental crucial primary differences