title: scale_fill_manual() will not change colors on legend?
body: <p>When I use <code>scale_fill_manual()</code> with ggplot, and specify certain values, the values on the legend both represent black shapes instead of the values that I specified in the code. So for example, if I specified <code>scale_fill_manual(values = c("red",NA))</code>, I would want the legend to show a red shape and a black unfilled one, but both shapes are black. Anyway to customize the legend in this way?</p>
  
  <p>Dates data:</p>
  
  <pre><code>c(12/31/2020,12/31/2021,12/31/2022,12/31/2023,12/31/2024,12/31/2025,12/31/2026
  12/31/2027,12/31/2028,12/31/2029,12/31/2030,12/31/2031,12/31/2032,12/31/2033
  12/31/2034,12/31/2035,12/31/2036,12/31/2037,12/31/2038,12/31/2039,12/31/2040
  12/31/2041,12/31/2042,12/31/2043,12/31/2044,12/31/2045,12/31/2046,12/31/2047
  12/31/2048,12/31/2049,12/31/2050,12/31/2051,12/31/2052,12/31/2053,12/31/2054
  12/31/2055,12/31/2056,12/31/2057,12/31/2058,12/31/2059,12/31/2060,12/31/2061
  12/31/2062,12/31/2063,12/31/2064,12/31/2065,12/31/2066,12/31/2067,12/31/2068
  12/31/2069)
  </code></pre>
  
  <p>Example code and output:</p>
  
  <pre><code>dat &lt;- read.csv("Dates.csv")
  a &lt;- data.frame(date = dat[1:15,1],income = c(rep(10000,5),rep(40000,5),rep(100000,5)),
                  family = c(rep("true",5),rep("false",5),rep("NA",5)),
                  status = c(rep("low",5),rep("medium",5),rep("high",5)),
                  state = c(rep("TX",5),rep("PA",5),rep("CA",5)))
  a$date &lt;- as.Date(a$date,format = "%m/%d/%Y")
  ggplot(a,aes(x = date,y = income)) +
    geom_point(aes(color = state,fill = status,shape = family),size = 1) +
    scale_fill_manual(values = c("red","green",NA)) +
    scale_color_manual(values = c("red","green","brown")) + 
    scale_shape_manual(values = c(22,21,25))
  </code></pre>
  
  <p>RESULT:</p>
  
  <p><a href="https://i.stack.imgur.com/oHLBj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oHLBj.png" alt="enter image description here"></a></p>
  
  <p>PROBLEM:</p>
  
  <p>Why is the fill section (status) of the legend black for all shapes? How to fix/customize that part?</p>