R Leaflet Legend: specify order instead of alphabe

I added legend to r leaflet code and output is this

I would like the order to be

GREEN "More than 66%"
ORANGE "Between 33% and 66%"
RED "Less than 33%"

Code

sep <- read.csv("31R_SEP_assets_csv - Copy.csv")

Sub1 <- sep[grep("SEP.12", names(sep))]
sep$newCol <- 100*rowSums(Sub1)/rowSums(sep[4:7])

# create a new grouping variable
Percent_SEP12_Assets <- ifelse(sep[,8] <= 33, "Less than 33%", ifelse(sep[,8] >= 66, "More than 66%", "Between 33% and 66%"))

Color_Assets <- colorFactor(c("darkgreen","darkorange","darkred"),
                               levels = Percent_SEP12_Assets,ordered=FALSE)

leaflet(data = sep[]) %>% 
  setView(lng = mean(sep$Longitude), lat = mean(sep$Latitude), zoom = 12) %>% addTiles()  %>%
  addCircleMarkers(~Longitude, ~Latitude,  color = ~Color_Assets(Percent_SEP12_Assets),  popup = ~as.character(paste(Site, Percent_SEP12_Assets , sep=", "))) %>%
  addLegend("bottomright", pal = Color_Assets, values = Percent_SEP12_Assets, title = "SEP 12 Installs")

dput(sep)

structure(list(Site = structure(1:5, .Label = c("Staten Island\\31R001", 
"Staten Island\\31R002", "Staten Island\\31R003", "Staten Island\\31R004", 
"Staten Island\\31R005"), class = "factor"), Latitude = c(40.508874, 
40.577256, 40.520825, 40.552373, 40.529697), Longitude = c(-74.244048, 
-74.100135, -74.211845, -74.195516, -74.187532), Windows.SEP.11 = c(63L, 
174L, 11L, 85L, 163L), Mac.SEP.11 = c(0L, 1L, 4L, 0L, 0L), Windows.SEP.12 = c(124L, 
185L, 9L, 75L, 23L), Mac.SEP.12 = c(0L, 1L, 32L, 1L, 0L), newCol = c(66.3101604278075, 
51.5235457063712, 73.2142857142857, 47.2049689440994, 12.3655913978495
)), .Names = c("Site", "Latitude", "Longitude", "Windows.SEP.11", 
"Mac.SEP.11", "Windows.SEP.12", "Mac.SEP.12", "newCol"), row.names = c(NA, 
-5L), class = "data.frame")

Thank you!

# create a new grouping variable
Percent_SEP12_Assets <- factor((sep[,8] > 33) + (sep[, 8] >= 66), labels = c("Less than 33%", "Between 33% and 66%", "More than 66%"))

Color_Assets <- colorFactor(c("darkred","darkorange","darkgreen"),
                           levels = Percent_SEP12_Assets,ordered=FALSE)

Factor with order required. I've also replaced the ifelse with a sum of logical expressions.