It's the tech from Performance Reviews!
Hi,
Glad to share my research with you—from sources other than Hoover's own spec's sheets, so it is likely not

% but close:
For the bonus points ...
JADE GREEN-LIGHT, MEDIUM & TEAL GREEN or OYSTER WHITE models (color scheme used from 1979-88)—
Convertibles U4161-9, U4301, U4335, U4381-9, U4393 (US); Concept Ones U3105 (US), U4205 (US & CA); Celebrity QS S3189, S3193, S3199 (US); Spirit S3213, S3241, S3291 (US)
P. S. My general floor & surface care appliance interest wanes after the mid-1990s as does much of my research such as this. So there may be later models in the color scheme, too.