darker colours in d3heatmap

Question

I made a heatmap in heatmap.2 and d3heatmap with the same parameters and colour scheme; however, heatmap.2 shows much stronger colours while the colours in d3heatmap look washed out. Any idea what I could be doing wrong?

    hmcol<- colorRampPalette(brewer.pal(9, 'GnBu'))(100)[enter image description here][1]
    heatmap.2(assay(vst_tissue[head(order(-rowVars(assay(vst_tissue))),500),]),
         col = hmcol, Rowv = TRUE, Colv = TRUE, scale='none', dendrogram='both', trace='none')
    d3heatmap(assay(vst_tissue[head(order(-rowVars(assay(vst_tissue))),500),]),
         col = hmcol, Rowv = TRUE, Colv = TRUE, scale='none', dendrogram='both', trace='none')