Erythrodiplax umbrata is sometimes also called Band-winged Dragonlet. 
Males are quite distinct, with a black body and prominent wide black band across each wing at midlength.
Females and young males are yellowish to tan to khaki color, with a brown thorax and a vivid white midline. 
There are dark brown markings on each side of the abdomen, becoming larger to the rear and finally almost covering S8-S9. 
Terminal appendages (cerci) in both sexes are whitish.
A minority of mature females look like males, with black bodies and wing bands, but most females lack the black bands on the wings and just get darker and duller as they age. 
In young males the wing bands are visible as brown washes which darken slowly with age.

1st photo: A male
2nd & 3rd photo: A female.

Los Flamencos Sanctuary, La Guajira, Colombia, 1 November 2014