Colorbar not corresponding with bounds when plotting scatter

When plotting scatter and nocountourf=TRUE, the bounds appearing in the colorbar do not correspond with the bounds passed to map generator and they also appear moved with respect to the colorbar.

The code used is:

load("~/Documents/tmp/data_scatter_mg.RData")
lon_norm <- seq(-180,180,30)
lat_norm <- seq(-90, 90, 30)
colour_scatt = c("#0000FF", "#2424FF", "#4848FF", "#6D6DFF", "#9191FF", "#B6B6FF", "#DADAFF", "#FFAAAA", "#FF5555", "#FF0000")
bounds = c(-0.6, -0.5, -0.4, -0.3, -0.2, -0.1,  0.0,  0.1,  0.2,  0.3,  0.4)

pm$aplot(x = as.array(lon_norm),
         y = as.array(lat_norm),
         scatter_data = df3,
         nocontourf=TRUE,
         colors=colour_scatt,
         bounds=bounds,
         ticks=bounds)