The dipstick test for diabetes shows grey for ketones on the stick. But theres no grey colour on the scale, only pinks leading to purples.???

Expired? It is possible that the Urine Dipsticks u are using have expired or were contaminated rendering them useless. Urine dipstick tests for Ketones is not a diagnostic test for diabetes. U can develop ketonuria from fasting, dehydration, a low carb diet, as well as uncontrolled insulin dependent diabetes. Glucose into ur urine is suggestive of diabetes, though a fasting blood glucose is the best test.
Ketones. Urinary ketones are very nonspecific, which basically means they can only be interpreted within context. Most of the time they are not harmful. I am unsure how to interpret your scale without being able to see it in person. Best of luck :)
Probably normal. Almost certainly it's negative, or so weakly positive it doesn't matter. Even moderate to large urine ketone levels are normal in healthy people if they haven't eaten much during a few hours before testing. It doesn't mean anything for diabetes unless the glucose patch is at the highest possible level.