I think your problem might be in non-character hexadecimal values. Make sure they are the first. See the example below:
year <- 1:5
logtrans <- log(year)
size <- rep(15,5)
intel2 <- data.frame(HexLogClock=c("#330000", "#FFFFCC", "#660000", "#FF0000", "#00FF00"),stringsAsFactors=FALSE)
symbols(year, logtrans, circles=size, inches=0.05, bg=intel2$HexLogClock)
stringsAsFactors=FALSE, read.csv , .
, :
intel2$HexLogClock <- as.character(intel2$HexLogClock)