i passed my 1.3-1.6 (its only 22.8 percent increase according to Puspakom calculator) transplant inspection just last week. i went and did it myself, personally at puspakom. no coffee money involved, was asked, or needed. if u still wont take my word for it, god help u.
in my registration card, the car's color is white. i went to puspakom with my current red color. we had an elaborate conversation about this and the inspecting Puspakom officer told me there will be no problem regarding the color with JPJ. do it at your own leisure. if any enforcement officer asks for kopi money bcoz of the color, its clear he's just taking advantage of a loosely enforced law. its not an important 'looked at' rule (at the moment).
off topic;
i even told him (the puspakom officer) i changed 1 mounting position. he told me if it was cut at the body or welded in ANY way, he wont pass me.. so i told a LITTLE white lie (brown lie for malay? haha) that the mount brace is bolted onto the chassis following the halfcut; that i dont know more coz the mechanic kow tim for me. he bought it hahaha so lo and behold, i have a street and insurance legal car! :p
there is NO SUCH THING as 1.3 to 1.6 approval getting more difficult nowadays, all u have to make sure is there is absolutely NO body/engine mounting modification that involves even the slightest cutting or welding. the counter officer calculated my increase himself before issuing my queue number; its only 22.8%. Afterwards this is what he told me and i quote:
"atas 25% bukan tak boleh. boleh, tapi kena ambil borang khas dan apply guna surat" -end quote.
MY intepretation = transplants above 25% are permitted, as long as you request a special kind of inspection through the correct forms, write a show cause letter, and make sure your car complies to the criteria (no radical mounting mods, uprated suspension, uprated brakes to name a few)
coming back to the topic,
so far, car color has absolutely nothing to do with an engine transplant approval. as long as puspakom has passed your transplant, JPJ cannot have nuts to say about the car's color (unless they are EXTRA "$rajin$"). However, i am not saying u shouldnt be bothered about it at all. Keng already stated that it doesnt require any payment, so its a good thing to keep the pink slip up to date if possible. the choice is in ur hands. im just saying u wont be busted for it (unless u are very unlucky hahaha)
AND... my car has a black colored bonnet. :D