This is a pretty low level way of achieving it, if I correctly understand:

## Dummy data in ~bed format
n<- 10
chrom<- rep('chr1', n)
start<- seq(1, 1000, length.out= n)
end<- start + rpois(n, 50)
logfc<- rgamma(n, 2)

## Prepare colours based on logFC
pal<- colorRampPalette(c('blue', 'red'))
cols<- paste0(pal(n)[as.numeric(cut(logfc, breaks = n))], 99)

## Plot
plot(x= start, y= rep(0, n), type= 'n', bty= 'n', yaxt= 'n',
    ylab= '', xlab= 'Position', xlim= range(c(start, end)), ylim= c(0, 1))
rect(xleft= start, xright= end, ybottom= 0, ytop= 0.1, border= NA, col= cols)
text(x= start, y= 0.12, labels= sprintf("%.2f", logfc), adj= c(0,0))

## Legend
nlg<- 5
lgcols<- paste0(pal(nlg)[1:nlg], 99)
lg<- round(seq(min(logfc), max(logfc), length.out= nlg), 1)
legend('topleft', pch= 15, bty= 'n', col= lgcols, legend= lg, pt.cex= 2, cex= 1)

Maybe just export the UCSC browser shot directly from an existing session, or use a fetch tool, if automation is needed.