This is getting interesting. Regarding the regional differences, I've never had a southern curry (if the beer's anything to go by I don't think I'm missing much;D), but all the dansaks I've had have been on the yellow side of the curry spectrum, varying from nuclear sunburst yellow to orange/ochre depending on the amount of turmeric/colouring used. I've always assumed this reflected the fact that the dish features lemon/pineapple and split red lentils which cook out to a yellowy colour but obviously some places make it reddish so there you go.
The amount of lentils in the OP looks excessive, try about 3/4oz (100/125g) or about half a cup, should be enough for two generous portions. Red lentils should cook in roughly 3 times their own volume of water in about 25 mins, there shouldn't be any need to drain and blend them they should be cooked to a sort of thin pur?e (if only cooked for 10 mins they are underdone and like all undercooked pulses can give rise to uncontrollable and potentially embarrassing flatulence

).
Hope this helps
Regards
CoR