A backlight (10; 710) comprising: a front and back reflector (12, 14; 712, 714) forming a light recycling cavity (16; 716), the front reflector (12; 712) being partially reflective to provide an output illumination area; and one or more light sources (24a, 24b, 24c) disposed to emit light into the light recycling cavity (16; 716); wherein the front reflector (12; 712) has a hemispherical reflectivity for unpolarized visible light of R f hemi, and the back reflector (14; 714) has a hemispherical reflectivity for unpolarized visible light of R f hemi, and R f hemi ∗ R b hemi is at least 0.65; and wherein the front reflector (12; 712) has a sloped transmission spectrum at a view angle of interest Ω, wherein the sloped transmission spectrum has a difference between a maximum transmission spectrum bin value of three visible wavelength bins divided by a 3-bin average of three transmission spectrum bin values and a minimum transmission spectrum bin value of the three visible wavelength bins divided by the 3-bin average of the three transmission spectrum bin values that exceeds 15%, wherein the three visible wavelength bins correspond to wavelength ranges of 420nm to 475nm, 505nm to 610nm, and 555nm to 635nm, and wherein the transmission spectrum bin values for the three visible wavelength bins are averages of transmission values for the respective wavelength range, and wherein a backlight intensity spectrum T Ω λ / 1 − R b hemi λ ∗ R f hemi λ is neutral, where λ denotes wavelength, where T(Ω, λ) is a ratio of a transmitted intensity at an angle centered on the view angle of interest Q relative to a front reflector plane, with the front reflector and an absorbing polarizer overlaying an all-angle light source, to an intensity at 0 degrees for only the absorbing polarizer overlaying the all-angle light source, and where the neutral backlight intensity spectrum has a difference between a maximum backlight intensity spectrum bin value of the three visible wavelength bins divided by a 3-bin average of three backlight intensity spectrum bin values and a minimum backlight intensity spectrum bin value of the three visible wavelength bins divided by the 3-bin average of the three backlight intensity spectrum bin values that is less than 15%, wherein the backlight intensity spectrum bin values for the three visible wavelength bins are averages of backlight intensity values T(Ω, λ)/{1-R b hemi (λ) ∗ R f hemi (λ)} for the respective wavelength range. a front and back reflector (12, 14; 712, 714) forming a light recycling cavity (16; 716), the front reflector (12; 712) being partially reflective to provide an output illumination area; and one or more light sources (24a, 24b, 24c) disposed to emit light into the light recycling cavity (16; 716); wherein the front reflector (12; 712) has a hemispherical reflectivity for unpolarized visible light of R f hemi, and the back reflector (14; 714) has a hemispherical reflectivity for unpolarized visible light of R f hemi, and R f hemi ∗ R b hemi is at least 0.65; and wherein the front reflector (12; 712) has a sloped transmission spectrum at a view angle of interest Ω, wherein the sloped transmission spectrum has a difference between a maximum transmission spectrum bin value of three visible wavelength bins divided by a 3-bin average of three transmission spectrum bin values and a minimum transmission spectrum bin value of the three visible wavelength bins divided by the 3-bin average of the three transmission spectrum bin values that exceeds 15%, wherein the three visible wavelength bins correspond to wavelength ranges of 420nm to 475nm, 505nm to 610nm, and 555nm to 635nm, and wherein the transmission spectrum bin values for the three visible wavelength bins are averages of transmission values for the respective wavelength range, and wherein a backlight intensity spectrum T Ω λ / 1 − R b hemi λ ∗ R f hemi λ is neutral, where λ denotes wavelength, where T(Ω, λ) is a ratio of a transmitted intensity at an angle centered on the view angle of interest Q relative to a front reflector plane, with the front reflector and an absorbing polarizer overlaying an all-angle light source, to an intensity at 0 degrees for only the absorbing polarizer overlaying the all-angle light source, and where the neutral backlight intensity spectrum has a difference between a maximum backlight intensity spectrum bin value of the three visible wavelength bins divided by a 3-bin average of three backlight intensity spectrum bin values and a minimum backlight intensity spectrum bin value of the three visible wavelength bins divided by the 3-bin average of the three backlight intensity spectrum bin values that is less than 15%, wherein the backlight intensity spectrum bin values for the three visible wavelength bins are averages of backlight intensity values T(Ω, λ)/{1-R b hemi (λ) ∗ R f hemi (λ)} for the respective wavelength range.