For what it's worth, there are drawings of HMS Caesar and HMCS Sioux on Pg 2 of Alan Raven's Camouflage Vol 3. Both drawings depict the ships wearing the Emergency Fleet Scheme for Destroyers used into 1944 for destroyers in home waters: Caesar in G10, G45, and White; Sioux in G20, B30, G45, and White.
Based on photos that I have, Caesar's pattern appears to be a direct match for both Haida and Huron in 1944. The pattern for Sioux is slightly different and on the photos I couldn't make out four different colours - not to suggest that they aren't there.
I recently converted a Haida from the old Revell 1/720 kit. Like you, I live in Canada and don't have access to the Sovereign Colours paint line, but I used their magnificent paint colour chart (thanks James!) to come up with these approximate matches allowing for some scale colour:
G10: Tamiya XF75 IJN Kure Grey
G45: Vallejo Model Air 71.050 Light Grey
White: Model Master Light Gray FS36495.
I did the decks with:
Tamiya XF77 IJN Grey Sasebo
Tamiya XF54 Dark Sea Grey - walkways
I was happy to find drawings that would work and am not too concerned with exact colour shades. I like the look of grey decks and am quite happy with the results. I hope this helps.
As an aside, I also did a conversion to HMCS Iroquois using the Revell kit. There is a drawing of Iroquois on Pg.28 in Alan Raven's RN Camouflage Vol 2 which I used:
507A: Tamiya XF75 IJN Kure Grey
507C: Vallejo Model Air 71.050 Light Grey
B5: WEM US07 5S Sea Blue
I note that IHP's kit of HMS Colossus also suggests using Vallejo Model 71.050 for 507C, a happy coincidence I found after finishing Haida and Iroquois.
I went with the major conversion option after finding that the RCN Tribals had different bridges and after superstructures than the RN Tribals, which alas Trumpeter missed.
The basic Revell kit has 38 parts, both conversions had nearly 300 - custom laser cut, 3D printed, and scratch-built. The results of having a really good set of plans of Haida and not knowing when to quit!